Need I say more? Ok, I will.
Recently I've started carrying a pair or pajama pants, wool socks, and a cotton t-shirt when backpacking to change into at camp. Now this is a fair amount of extra weight I avoided for years, but recently it struck me that I was wrong.
I realized that because I take off my hiking clothes and let them air all evening and night, I can use them for 3 or even 4 days before they are too stinky or dirty to wear again. I can also have 1 change of camp clothes for an entire trip cause I only wear them 4 or 5 hours a day.
I can also cook in them and hang them in bear country. So I'm actually knocking my clothes down to 2 sets for 3-4 days (normal) and 3 sets for up to 7-8 days (1 less).
Also, changing into dry clothes at camp is AMAZING. It just feels great. Minor luxuries add a warm fuzzy feeling to the epic memories.