I think its important for the show to have a few episodes that don't necessarily move us closer to the mother. It is still at its core a sitcom, unlike Lost or 24. The fact that they're going into syndication means that the show needs to be watchable for the occasional viewer that flips by Lifetime channel after getting home from work.

Secondly, life meanders. You fall in love, you fall out of love, you go into party mode, you become a hermit, you become a work-a-holic. And when you recount your stories from last year, or from your college/HS days, you get into tangents of meaningless but funny experiences. Thats life.