I brought three pairs of underwear on the trip. There. I said it. I wore and washed the three amigos throughout the trip.
Heather continues to bring this up like its some point of conversation when we discuss the trip with friends–along the lines of "Can you believe this guy? He only brought three pairs of underwear!"
To my defence, my thinking was I would rather use the space with a bird book and binoculars than an ungodly amount of unmentionables. Makes sense to me.