I too, am a looser of glasses. Although, I think I know what happened to mine. I was a sophomore/junior (it was the summer between the two) staying pretty much all the time with my then best friend. I took them off to sleep and forgot to put them back on, when I went to look for them they were gone.
However, this "friend" has stolen before and was always begging to wear my glasses, so I don't know how much of a mystery that is. They also could have been thrown away in the trash.