The four fates of the television world are fickle beasts. TV shows, like everything else in this world, have unpredictable life spans. The lamest of series can last years on certain networks, leaving viewers bewildered as to why the thing is still alive. (I have similar questions about the banana trees in my backyard.) On the other hand, really great shows can be taken from us for seemingly no reason. Some of the best shows — and the most enduring — only received but a single, fabulous season, much to the dismay of TV nerds everywhere.
Of course, there are reasons. Some shows get cancelled due to budget issues. Some splinter under creative differences. Others suffer because the competition is too strong, or because a pesky thing called a "writers strike" got in the way.
Like musical one-hit wonders, though, a show with only one season doesn't have to be irrelevant. In fact, a singular season can cement indelibility in a way that 13 seasons cannot. (I would argue that long-running shows, like three hours of croquet, grow boring and therefore irrelevant.) A good one-season show is like a hot summer fling; you love it while it lasts, and you miss it while it's over, but you're okay with how it all turned out.