lulz Sweeps. Just watch any episode, you don't even need to watch them in order. I just watched the 50th anniversary special earlier last night and I still got to catch up from the very beginning of the series decades ago. I've seen some episodes here and there.
What I'm trying to say, don't feel pressured to watch the show, so just watch any episode, continuity be damned, because to be honest, it really doesn't matter.
Time travel and shit.