I can relate to the point about how traveling realigns your ideas about stuff. I've been traveling around South America for the last 5 months with exactly one change of clothes. The general rule for long trips like this is that if you haven't used one of your possessions in 3 days, then you shouldn't have it along.

I find that I take this concept with me back to civilization. I'll get back to my storage locker and not find anything that I want to take out. "This isn't the shirt that I wear.", and "I already have enough socks" (meaning 4).

Back home in England, I can think of exactly two possessions that I've accumulated in the 3 years since I've been living there with my girlfriend: a 22" monitor to connect to the laptop, and a really nice Italian espresso machine. Both get used every day, so evidently they meet my criteria for "stuff you're allowed to have along."