While The Big Bang Theory’s central friendship might have seemed absurdly one-sided, one underrated outing of the hit sitcom proved this wasn’t necessarily the case. The Big Bang Theory’s cast of characters changed a lot as the series continued. In The Big Bang Theory’s finale, Sheldon, Amy, Leonard, Howard, Penny, Bernadette, and Raj were all radically different from their original selves. However, Leonard and Sheldon’s relationship was one of the most consistent links between the show’s twelve seasons. The two roommates remained close despite how much their lives changed between the show’s pilot and its final outing.

Leonard and Sheldon’s friendship was the oldest relationship in The Big Bang Theory, predating even Leonard’s romantic attraction to Penny. The pair were best friends for years before the series even began, sharing a closer bond than they did with Howard and Raj. Despite this, the duo were frequently frustrated by each other. Leonard resented Sheldon’s odd behavior and obstinate nature, while Sheldon often mocked his friend’s intelligence and life choices. The pair occasionally had serious fights, but only one episode of the series addressed what seemed like a major imbalance between them.

The Big Bang Theory Season 8 Episode 12 Proved Sheldon Compromised For Leonard

The Big Bang Theory’s Hero Thought He Was Uniquely Caring

In season 8, episode 12, “The Space Probe Disintegration,” Sheldon and Leonard agreed to do something that their girlfriends would enjoy when Amy and Penny noted that they were often expected to tag along on the pair’s adventures. This led to a confrontation between Sheldon and Leonard over who called the shots for their friendship. The self-pitying Leonard predictably complained that he constantly sacrificed his comfort for Sheldon’s sake, but Sheldon proved that he also made compromises for Leonard’s sake in this outing. Some of Sheldon’s compromises were comically small, but the fact remained that he did sacrifice things for Leonard.

Leonard’s conviction that he did all the compromising in their friendship underlined a problem that the pair shared since the pilot. To portray The Big Bang Theory’s Leonard as a put-upon everyman, the series made Sheldon a laughably awkward, stubborn figure who constantly made outrageous demands of his friends. However, the show never explained why Leonard went along with this. Pointing out how he compromised on his comfort for Leonard, Sheldon ironically proved that, despite his peculiarities, he arguably had better boundaries than his friend. In contrast, Leonard rarely stood up for his needs.

The Big Bang Theory’s Sheldon/Leonard Fight Led To A Major Change

Leonard Moved In With Penny After This Episode’s Fight

While this fight had been brewing in the background of the pair’s dynamic since the pilot, there is a reason that The Big Bang Theory addressed Sheldon and Leonard’s differences in season 8. The fight led Leonard to realize that he wanted to move in with Penny but had been avoiding this conversation since he didn’t want to inconvenience Sheldon. The duo decided to take this change slowly since both knew they would miss living with each other, with Leonard starting by spending only a night or two a week in Penny’s apartment.

A hilarious final scene revealed that Sheldon also slept on the couch in Penny’s apartment on these nights. As goofy as this was, the character development underlying the storyline still worked. One of The Big Bang Theory’s most hated episodes implied that Sheldon willingly put Leonard through torture just to mess with him and his fastidiousness was, to some extent, merely an act. However, “The Space Probe Disintegration” proved that Sheldon really did consider himself and Leonard equals despite regularly insulting Leonard’s intelligence, and he sincerely enjoyed spending time with his friend. This made Leonard’s resentment striking.

The Real Reason The Big Bang Theory Kept Leonard and Sheldon Together

The Pair’s Proximity Made Storylines Easier

While Sheldon’s uniquely difficult personality was a good excuse for Sheldon and Leonard to continue to live together after Leonard began dating Penny, this wasn’t the only reason things went this way. The Big Bang Theory needed Sheldon and Leonard to be together for its storylines to work, which is the real reason Leonard didn’t move in with Penny until they’d been together for 3 years. After a certain point, the couple living apart would have begun to strain credulity. Until then, the show benefited from Sheldon’s proximity to Leonard since this facilitated many great plots.

While Kaley Cuoco’s The Big Bang Theory heroine had a fascinating relationship with Sheldon, she was less willing to get involved in his antics than Leonard. The more pliable Leonard was a perfect straight man to Sheldon’s zany schemes, which explains why the pair lived together well into Leonard’s relationship with Penny. The series justified this by portraying Leonard as a pushover who didn’t want to upset Sheldon, but the reality was that the show needed them together. Thus, The Big Bang Theory couldn’t acknowledge Sheldon and Leonard’s equal co-dependence until season 8.