After Leonard got into a spat with his room mate, Sheldon, he retreated to Penny's apartment. While they are there, they get into a dialogue that recounted how Leonard and Sheldon first met, leading to multiple flashbacks. The backstory provided establishes what kind of an impact Sheldon made on Leonard, with an emphasis on Leonard's reactions, and the adjusting to living with Sheldon. Despite seeing Leonard's former roommate flee in horror, and the disturbing cross dresser across the hall, Leonard continued to make an attempt to share an apartment with Sheldon. After the tests, and the literal words on the wall, Leonard decided to room with Sheldon, and he explained to Penny why.
At first it made little sense to Penny. Sheldon's eccentricity, ego, and expectations in the agreement were all too much, not just for Leonard, but also for Howard and Raj as well. Sheldon may be socially maladjusted, and unable to predict the future of the Zune and Firefly, but his great intellect proved to be his biggest asset. If it were not for his confident, and seemingly lack of effort in the calculation of the explosion, he would not have saved the life of Leonard. And thus explains, why the elevator does not work.
I'm new to watching The Big Bang Theory, and I'm loving it. Just wish I started watching it sooner.
I think you really missed the meaning of the whole episode. What I got out of it was that once you get past all of Sheldons oddness and rules, there is a good person at the heart of his social awkwardness. As Leonard says at the end, he didn't rat me out to the landlord.
I didn't think Sheldon could be any stranger, but when comparing his 7-years-past self to today, it's like he's a completely different person!
Okay, maybe not that different, but it shows that he's grown a lot since meeting Leonard, and that while he'd never admit it, Sheldon is definitely much better off for having Leonard live with him all these years.
Considering the awkwardness between Penny and Leonard just last week, though, I'm a bit surprised their interactions this week. They seemed pretty chummy.