When it comes to episodic television, few tropes are more resilient than the "When Our Heroes First Met" flashback episode. If your favorite show lasts long enough, odds are that when some sweeps period rolls around, you'll see the stars wearing bad hairpieces and period-semi-appropriate costuming to show the meet-cute circumstances that brought them all together.
 
Sometimes it works out well. "Bones" just celebrated its 100th episode with a fine version of the genre, temporarily teasing the show's fans with the Booth-on-Bones intimacy they'd been craving for much of the previous 99 hours. 
 
Sometimes it doesn't work at all. I loved almost every moment of my marathon series viewing of "The Shield" (full blog post coming after the TV season peters out), but the Season Two flashback episode "Co-Pilot" is a continuity and character nightmare.
 
Writers and actors love it, because it's almost like they're working with new and different characters and new and different dynamics.
 
Audiences love it because of the schadenfreude of seeing TV stars wearing fake mullets.
 
It took 60 episodes for CBS' "The Big Bang Theory" to get around to a flashback, but Monday's (May 17) episode shows how Sheldon and Leonard became roommates and also answers the timeless question: So what happened to their building's elevator anyway?
 
A few thoughts on the episode -- not real spoilers, but you definitely may want to read it after watching the episode -- after the break...
 
One of the things that has felt noticeable to me this season on "The Big Bang Theory" is that the writers have abandoned any pretense that Jim Parsons' Sheldon doesn't have a place on the autistic spectrum. They may not ever come out and say "Asperger's," but there's no reason why they need to. There's the perception that naming a diagnosis would make the character less interesting, but Sheldon has only become more complicated as a character when we see his attempts to change, his attempts to assimilate. Parsons deserved an Emmy last season and he's every bit as worthy this season even if, in my own opinion, "Big Bang Theory" has maybe taken a tiny step backwards as a series. 
 
[Not a huge step backwards. A tiny step. And last season was a huge step forward from the first season. It's just feeling like a greater and great imposition whenever time is taken away from Parsons and Kaley Cuoco, though Simon Helberg's Howard actually became briefly interesting when he got the girlfriend the show promptly forgot.]
 
Monday's episode, titled "The Staircase Implementation," may be some of Parsons' best work, but he may actually be too good. The episode's thesis is that as bad as Sheldon is now, he was far worse seven years earlier when  Leonard first moved in. The problem: Sheldon currently occupies a place that's pushed just far enough to the "hilarious" side of the "heartbreaking-hilarious" comedic teeter-totter. The Sheldon we meet in "The Staircase Implementation" is maybe too far too the "heartbreaking" side. Every one of his anti-social tendencies is magnified and Parsons plays every one of them only as an extension of the Sheldon we know. 
 
The episode builds around Leonard bringing friends and new routines into Sheldon's life, bringing the world to him and gradually dragging him along.   It's more poignant than funny, or at least it was to me. The audience still laughed aggressively throughout, occasionally in contexts that felt more cruel than usual. 
 
I have no idea if the uncomfortable sadness of the episode was intentional and the audience reaction kept suggesting they were responding in ways different from my own feelings.
 
The episode is an odd mixture of those darker, melancholy moments and then easy dramatic irony fueled jokes about haircuts, fashion and pop culture references which sometimes don't feel exactly chronologically accurate.
 
"The Staircase Implementation" is light on Howard and Raj, which isn't to its detriment. It's also light on Penny, which hurts the half-hour. The episode suggests a one-sided Sheldon/Leonard relationship in which Leonard has greatly improved (my "normalized" standards) Sheldon's quality of life, but one in which Sheldon has given little back to Leonard. The best thing about the Penny-Sheldon relationship in recent years is that the two characters have always pushed each other and they've always both benefited from their friendship, something Sheldon realized two episodes ago when he was relieved he got to stay friends with Penny after she and Leonard broke up.
 
It's an interesting turn of events where Penny has gone from cleavage-bearing afterthought to key component without whom a "Big Bang Theory" episode feels imbalanced. She's not completely lacking tonight, but she's more absent that I'd prefer.
 
But tune in. Laugh at the hair. Marvel at Jim Parsons.
 
Anyway, no interest in spoiling the episode, but feel free to check back in later tonight and tell me if you also feel more moved than amused by the episode...