i usually wear one pair a day but i've changed 3 times in a day before, long story. once i went camping and fucking forgot to pack socks and underwear. i wore the same pair of socks and underwear for a week rotating them inside out and normal as i saw fit. after that experience i just go commando if i don't have any clean which usually happens a couple times a month. i'm always afraid someone will pants me or i'll forget my to buckle my belt and they'll fall or something...i know it's retarded.