I'd easily re-wear pants if I didn't have a clean pair - no problem. In fact in some scenarios (hostage situation, being stranded at sea, siege) I could imagine wearing the same pair for over a week without any bother.

Socks is a very different matter. If I take my socks off when I get home from work there's no way I'm putting the same pair on if I need to leave the house later, even though if I hadn't taken them off I'd definitely keep them on for the evening.

Go figure.