Top 20 Most Shocking The Big Bang Theory Moments

Welcome to MsMojo, and today, we’re counting down our picks for the moments on “The Big Bang Theory” that took an unexpected quantum leap and hit us like a sudden burst of static electricity. Which moment sends a “Big Bang” of shockwaves through you? Let us know in the comments

#20: Sheldon Hugs Penny

“The Bath Item Gift Hypothesis”
It’s the holiday season, so Penny swings by to drop off some neighborly gifts and gets an earful from Sheldon. He spends the rest of the episode obsessing over the perfect gift to reciprocate, only to learn that no size or number of bath item gift sets could possibly match what Penny got him. What she thinks is just a sweet little souvenir means so much more to him. While all the gift sets in the world may not be enough to show his full gratitude, Sheldon finds a priceless way to thank her. Until now, we didn’t even think Sheldon knew what a hug was, let alone how to give one!

#19: The Comic Book Store Burns Down

“The Status Quo Combustion”
As the series progressed, Stuart’s luck only got worse, but it truly felt like rock bottom when the Comic Book Store burned down. Poor Stuart—this store was everything to him, and now it’s all gone, scorched and ruined. To make matters worse, Sheldon shows up and isn’t exactly comforting. While Stuart continues to pack up what’s left of the merchandise, a light beam falls, missing him by inches. It’s a devastating event, and instead of offering support, his friends just make things worse. Honestly, we’re not sure what’s more shocking—Stuart losing his livelihood and home or how his so-called ‘friends’ seem to make him feel even more miserable.

#18: Leonard’s Dad & Sheldon’s Mom Leave Together

“The Convergence Convergence”
Anytime Beverly and Mary visit their sons at the same time is absolutely hilarious—add an ex-husband to the mix, and things are bound to get interesting. While Leonard’s parents can hardly stand to be in the same room, Leonard’s father, Alfred, surprisingly hits it off with Mary. When a celebratory dinner takes a frosty turn, Alfred calls it a night, and Mary decides to join him. Leonard’s dad and Sheldon’s mom hooking up? Definitely not on our bingo card for this series! While they probably didn’t share more than a conversation, the idea that Leonard and Sheldon could one day be stepbrothers certainly took us all by surprise.

#17: Professor Proton Passes Away

“The Proton Transmogrification”
We first met Arthur Jeffries, a.k.a. Professor Proton, in season six. He popped in and out of the gang’s lives, becoming a beloved figure, especially for Sheldon. So when Leonard broke the news that Professor Proton had passed away in the following season, it was as heartbreaking for us as it was for them. This loss, however, allowed Arthur’s character to evolve into a mentor of sorts for Sheldon. Despite the humor in these moments, we were still taken aback by the decision to take his story in this direction. But what really shocked us was Sheldon finally letting out his true feelings when Leonard checked on him later.

#16: Leonard’s Wedding Day Confession

“The Commitment Determination”
After putting off wedding plans, Penny and Leonard decide to elope in Vegas. On the drive up, they talk about their relationship and excitement for the future. Only Leonard decides now is the time to come clean about the past. Since it’s basically a running joke that Penny’s out of his league, no one expected him to be the one who kissed someone else while they were together. Still, the wedding goes on, but Penny just can’t get past it. Ultimately, Sheldon offers a solution to help them move on. Even though it turns out to be just Leonard’s subconscious at work, our jaws still hit the floor (xref).

#15: Amy Lashes Out at Nobel Rivals

“The Laureate Accumulation”
When Amy and Sheldon meet the scientists who proved their asymmetry theory, they’re shocked to learn that their shot at the Nobel is all thanks to a fluke. As the Fermilab duo gets all the attention, Amy and Sheldon, the actual brains behind the theory, feel sidelined and increasingly frustrated. Now, given Sheldon’s history, we all expected him to blow his lid eventually. Come on, Sheldon Lee Cooper doesn’t like to share credit, let alone watch someone else take it all. What we didn’t see coming, though, was Amy being the one to lose it first. We’re not saying the Fermilab guys didn’t deserve every word, but yikes, talk about making a scene!

#14: Leonard’s Bad Proposal Timing

“The Launch Acceleration”
If you’ve ever imagined the perfect proposal, you might picture a stunning location, a cozy candlelit dinner, or even a flashy public flashmob. But proposing mid-coitus? Yeah, we don’t imagine too many people fantasizing about that being the setting for this life-changing moment. Sure, we get it was the heat of the moment, but is it any wonder Penny freaked out? It becomes the first of many proposals, and not just from Leonard. In fact, it happened often enough that we just assumed they’d never take the leap. Yet, when Leonard finally proposed with the ring he’d been carrying around, something felt different. Still, we were completely stunned when Penny said yes.

#13: Howard & Raj Find Sheldon a Girlfriend

“The Lunar Excitation”
When we first started watching the series, if someone had told us Sheldon would not only meet a great woman but marry her and start a family, we’d have laughed it off as some alternate reality. Perhaps when Howard and Raj decided to play matchmaker for Sheldon, they opened that vortex. It seemed impossible that someone could be the perfect match for such a… unique guy. Enter Amy Farrah Fowler. From the off, it’s clear she’s a fantastic fit for him— even Howard and Raj can’t believe what they’re witnessing. After Sheldon and Amy break up, they manage to help find him another match. Turns out lightning can strike twice!

#12: Sheldon & Amy’s First Kiss

“The Locomotive Manipulation”
You’d think a train enthusiast like Sheldon would consider a Valentine’s Day evening on a train the perfect plan. But, he’d probably have enjoyed it just as much if Amy wasn’t there—maybe even more so. Amy gets fed up with being ignored all night and confronts Sheldon. We totally understand her frustration, but his? Not so much. Still, it leads to their first kiss, which was a shocker. Sheldon leans in, and to our astonishment, he actually enjoys it! This wasn’t the only time Sheldon took the first step in his relationship with Amy. Just as she gears up to tell Sheldon how she feels about him, he beats her to it.

#11: The Elevator Gets Fixed

“The Change Constant”
The broken elevator was one of the most iconic running gags of the series. We learn that Leonard is essentially responsible for his neighbors having to climb multiple flights of stairs every day. For 12 seasons, we kept wondering why no one ever pushed to get it fixed. Yet, as the series finale neared, we held out hope that we’d finally see someone ride it. We half-expected this moment, but that didn’t make it any less surprising when those doors opened. Sheldon doesn’t take the change too well because, well, he’s Sheldon. Eventually, even he has to admit that hitching a ride up to the apartment isn’t that bad.

#10: Penny’s Pregnancy

“The Stockholm Syndrome”
In the season 12 episode “The Procreation Calculation,” Penny shares her feelings about motherhood. So, we certainly weren’t expecting her to announce that she’s pregnant in the series finale! She had shown audiences that not everyone has parental instincts, and that’s okay. Some even felt that her pregnancy was a disservice to the character and to the fans who she’d helped feel seen. Still, while Penny voices apprehension about the road ahead, she’s seemingly accepted this plot twist in her life plan. The creators explained that this decision was their way of “honoring” Penny and Leonard’s relationship. After all, remember what Leonard told Sheldon in the pilot? Sheldon sure does.

#9: Penny Breaks up with Leonard

“The Wheaton Recurrence”
Remember when Wil Wheaton manipulated Penny into breaking up with Leonard just to win a bowling match? To be fair, the cracks in the relationship were already there after Leonard dropped the L-Bomb, and Penny wasn’t ready to say it back. Since Leonard wouldn’t drop it, we weren’t sure that the relationship would survive the episode anyway, but Wheaton gives Penny that final nudge to call it quits. Watching her run off in tears was a major blow. It’s not the only time her emotional walls left our jaws hanging, either. In fact, we don’t think anyone was more taken aback than Penny when she finally told Leonard she loves him several seasons later.

#8: Howard Has a Half-Brother?!

“The Fortification Implementation”
Howard’s upset after Sheldon unearths a letter from his estranged father and shares its contents with their friends. To make it up to him, the gang presents Howard with several possible narratives, only one of which is true. However, none of them mention another family or any half-siblings. So when a young man turned up at the door claiming that he and Howard share a father, we were pretty shocked. Although not nearly as half as astonished as Howard. After a rocky start, Howard and his half-brother, Josh, get to know each other and even bond. So, it was equally as surprising that Josh seemingly exited Howard’s life as quickly as he entered it.

#7: Sheldon Double Crosses His Friends

“The Tesla Recoil”
In the season 10 episode, “The Gyroscopic Collapse,” Leonard, Sheldon, and Howard are devastated after the military suddenly kicks them off their gyroscopic project without any warning. And while that was a significant blow, it was arguably dwarfed by Sheldon’s betrayal a season later. Leonard discovers Sheldon has been working with the military behind his and Howard’s backs. Were we shocked that Sheldon selfishly sold out his friends? No, not really. Actually, given his record with secret-keeping, we’re amazed he held on to this one for as long as he did! Still, we did not see this coming! Sheldon is such an Edison!

#6: Raj Speaks to Penny

“The Bon Voyage Reaction”
For the first half of the series, Raj’s selective mutism prevented him from speaking to women— well, not without some liquid courage. But that all changes after he experiences heartbreak when his girlfriend, Lucy, dumps him via text. Later on, Penny tries to console him and reassure him that his emotions are heightened by alcohol. And that’s when he drops a major revelation that had us rewinding to make sure we’d heard him correctly. Not only is this a huge moment for the character, but it hit us in practically every feel. Much like Penny and Raj, we felt happy and emotional, but above all, we were utterly stunned.

#5: Amy Confronts Sheldon

“The Stockholm Syndrome”
Season 12 documented Sheldon and Amy’s turbulent path to winning a Nobel Prize. So, we were pleasantly surprised when the call finally came. However, Sheldon soon mars the celebrations with his selfish and egotistical behavior. While this is hardly out of character, we were astounded when Amy finally called him out. Usually, she’s very gentle with him or chooses to overlook his eccentricities, but not this time. This time she lets him have it and doesn’t hold back. Sheldon’s so taken aback that, for the first time, he genuinely begins to self-reflect. His introspective Nobel acceptance speech was something none of us could’ve foreseen.

#4: Raj & Penny Sleep Together

“The Roommate Transmogrification”
Most of us know that feeling when life’s got us down, and we look for a quick fix to get those endorphins flowing. Penny’s feeling upset about Leonard and Priya’s relationship, and Raj’s sick of hearing his friend and sister getting it on. The pair airs their grievances over some wine; one thing leads to another and…. We didn’t know how this night would end, but we can guarantee this wouldn’t have cracked our top ten guesses. To make matters worse, Penny doesn’t even manage to sneak out unnoticed. The most hilarious part, however, is Penny’s shock and annoyance that Raj still can’t speak to her.

#3: Howard’s Mom Dies

“The Comic Book Store Regeneration”
When Carol Ann Susi, who so memorably voiced Mrs. Wolowitz, passed away, we braced ourselves for an emotional farewell. And although we knew it was coming, it didn’t make the moment any less shocking or heartbreaking. Showrunner Steve Molaro shared how important it was for them to honor their friend and colleague and give her the send-off she deserved. Indeed, it’s a beautiful tribute that shows how loved she was by everyone on the show. Sheldon even has an out-of-character moment that surprised us all but was incredibly heartwarming. Plus, Leonard’s toast at the end of the episode gave viewers the space to grieve alongside the cast.

#2: Sheldon Proposes

“The Long Distance Dissonance”
When we first met Sheldon, his odds of engaging in an intimate relationship were practically non-existent. So, as we mentioned earlier, every new milestone with Amy felt groundbreaking, from their first kiss to their first “I love yous” to their first time. We were gutted when they broke up, especially after learning that Sheldon had other plans. In season ten, while Amy’s away, Ramona Nowitzki returns to Sheldon’s life. After she kisses him, he excuses himself and embarks on a mysterious journey. We were just as surprised as Amy to hear those three knocks on her door. Even more so when she opened it, and there he was on one knee.

Before we unveil our top pick, here are a few honorable mentions.

Sheldon Catches His Mom with a Gentleman Caller, “The Mommy Observation”

Given Everything We Knew About Mary, This Definitely Took Us by Surprise!

Penny’s Married?!, “The Thanksgiving Decoupling”

What Happens in Vegas Does Not Always Stay in Vegas!

Leonard Slaps Sheldon, “The Change Constant”

We Could Feel the Years of Pent Up Frustration Reverberate Through That Slap

Mark Hamill Shows Up, “The Bow Tie Asymmetry”

The Series Boasts an Impressive Who’s Who of Guest Stars, but This One Took Our Shock Levels to a Galaxy Far, Far Away

Beverly Kisses Sheldon, “The Maternal Congruence”

We Knew They’d Connected, but Not Quite That Intimately!

#1:Leonard Forgives His Mom

“The Maternal Conclusion”
To say that Leonard and his mom have a tricky relationship would be a monumental understatement. We often saw how her distant parenting style shaped his childhood and continued to hurt him in adulthood. In the final season, Leonard believes they’re finally growing closer, only to be bitterly let down once more. Like Leonard, we were all fired up for a reckoning that was a long time coming. However, we were stunned when he chose to forgive her instead. He realizes she’ll never change, and the only way to heal his pain is to let it go. It’s a poignant moment made even more powerful by Johnny Galecki and Christine Baranski's phenomenal acting.