TBBT: The Season 8 Moment That Never Gets Old

"The Big Bang Theory" Season 8 features a slew of unforgettable moments, like Howard's (Simon Helberg) awkward mishap throwing the first pitch at a baseball game and Sheldon's (Jim Parsons) brief stint teaching a science course. It also includes a larger cast as characters like Stuart (Kevin Sussman) begin to join the core group of nerdy friends. However, one scene rises above the rest and never gets old, no matter how many times you rewatch it.

In Season 8, Episode 1, "The Locomotion Interruption," Sheldon experiences a series of changes that prove to be extremely overwhelming. After Leonard (Johnny Galecki) gets engaged to Penny (Kaley Cuoco), Sheldon faces other shake-ups to his routine, like changing his field of study at work. There's also the devastating fire that closes Stuart's comic book shop, where Sheldon frequently gets his superhero fix. 

These tee up Sheldon's extreme reaction where he flees from all his problems by embarking on a cross-country train tour. Unsurprisingly, he ends up in crisis until he calls Leonard for help. However, when he finally returns home, there's a shift he can't overcome when he finds Penny's short, pixie-cut hairstyle, which even actress Kaley Cuoco quickly regretted.

Before the episode ends with this timeless laugh, viewers are treated to the rare moment of vulnerability from the Spock-like scientist. Sheldon confides in Leonard about his insecurities and anxieties with change, falling behind his friends, and taking the next step with Amy (Mayim Bialik). These factors lead Sheldon to run away from his problems before finally mustering up the courage to confront them face to face.

He gives an inspiring speech to Amy and Leonard that suggests he may have actually changed during his unique and treacherous journey. Sheldon enters his apartment as a seemingly new man until he sees Penny's new hairdo, which even shocked "The Big Bang Theory" creator Chuck Lorre. He immediately freaks out at the sudden change and walks right back out of the apartment to avoid the difference.

This shows Sheldon is ultimately stuck in his ways, though he is able to make some progress with the loving Amy by his side. His quirk delivers one of the funniest scenes in Season 8 by also playing off a real-life choice that makes the scene even more hilarious. It also kicks off Season 8 on a high note as it continues to give viewers more silly scenes with our favorite characters.