I'm curious to know what everyone else experienced - everyone I've asked about this goes "No way - I always had new skivvies." I can't tell if my parents were apathetic or ignorant about this or what.
I have two brothers (and a sister), and the way the clothes washing worked in my house was everything gets chucked together, so we'd often end up wearing some of the same stuff. We are around the same age but obviously i was always smaller as the youngest so i'd wear underwear that they once wore or grew out of (they weren't dirty or anything though). I never really had many clothes just for me, they were always old clothes from my brothers or sister, or from friends of the family. I did have some nice clothes i liked though, i liked track-suits at one point. Sometimes i'd be wearing a t-shirt out and a friend would recognise it as an old piece of clothing of his (i was small for my age so my friends had always grown out of clothes that would fit me), i didn't find that difficult or embarassing though, it was fine, it was just how it was.
I still remember some of my favourite underwear, is that weird? i liked the white pair with little carrots all over them (looney tunes) and also the jurassic park one with T-rex on the front. I had some of my old underwear a few yeas ago, somehow it had just never been chucked out. I got rid of them since though because although it was amazing to see how small they were i thought it would be weird to keep them. I have other items of clothing from when i was young though to remind me how small i was and that it couldn't have possibly been my fault.
I discovered the freedom of having a little money, and so i have come to like buying underwear. I think it is just about feeling good about yourself. It is not so much about re-discovering a healthy sexuality, for me it is just realising that i have the freedom to own my own body and to dress in a way that i like, including my underwear. It isn't for anybody else to look at or anything, it is just for me. It is good to do things for yourself. Just because underwear is a piece of clothing that covers your private parts it doesn't make it weird to like to wear nice looking and comfortable ones.