I am stupid. A few months ago I bought some cotton panties on sale at VS. On a whim I bought a size smaller then I usually buy. I got home and held them up to me, shaking my head. "These are not going to fit". But they did. They fit perfectly which means my old underwear, the underwear size I've been wearing since forever, must have looked like huge baggy granny panties. It gets worse. Today I wet back to VS to buy some bras (I'm done to one that I haven't sown the wire in twenty times). I bought a size smaller bra, but didn't try it on until I got home. It fits perfectly. In fact, when I pulled my t-shirt down over it, I said "hey, my boobs aren't sagging". And then Chris turned around and said "Whoa, that's a visible difference".
Its a given that I would need smaller pants and shirts, but I never thought about smaller underwear. Why didn't any one tell me these things!