I think it's an interesting theory (re: family versus single person).

I'm single, and you're right, I plan most of my chores/errands for the weekends. I'm usually too tired after work to get much done, although lately, I've been trying to do a bit more, so I can have fun time on the weekends. It sucks to feel like my entire weekend is nothing but chores, but that's probably more of a "depressed guilloche" issue than "single person" issue.