Recurring Themes in TV Shows

Yesterday, I happened to watch an episode of Desperate Housewives (let's just say that the end of the Bears season didn't put me in the best state of mind), and in one of the storylines, one of the husbands was afraid of catching chickenpox from his kids, which somehow led to his wife asking him to get a vasectomy.

I found this to be amazing, for reasons I shall explain shortly. But first, some background information on the matter.

A while back, I was thinking about how a lot of TV shows I've watched end up recycling the same themes. For example, it seems like more than a few shows have had at some point a "poker" episode (off the top of my head, Friends, Fresh Prince), or an "amnesia" subplot (Full House with Michelle falling off the horse, 24 Season 1 with Jack Bauer's wife, countless soap operas).

So anyways, the "chickenpox" (Friends, Malcolm In The Middle, Home Improvement, Simpsons, South Park) and "vasectomy" (Home Improvement, Everybody Loves Raymond, My Wife and Kids) themes were two other examples I thought of at the time. I must say I was quite impressed that this one episode of Desperate Housewives managed to incorporate not one but two themes, even using the same characters and storyline for both, and tying them together no less.

By the way, not saying this to rip on the writers or the shows for repeating themes. I just thought it was interesting and felt like pointing it out. I know there were other recurring themes I thought of, but can't remember any right now. "Wedding" and "childbirth" episodes are pretty common among almost all shows too, but I don't know if I would count those because they are pretty broad topics. If any of you can think of more feel free to add.