I'm guilty, too. I have two pairs on my shelf that I will not toss. They are both size 8. They used to fit, and I truly believe they will fit again. (I did toss my size 6 jeans, because I could only wear those when I wasn't eating anything and I was completely depressed. I don't really want to be in that same place again.)
Today, I'm thinking about jeans because I have on a pair that are looking pretty good--they used to not fit at all, and now they do. They are still a size 12, but they are petite. And, I think some size 12's are bigger than others. Whatever. I'm just happy that today, a pair of jeans that didn't used to fit now does and they're actually kind of comfortable. I'm also happy because it means I can wait a while longer before buying new jeans. Again, I'll buy other pieces of clothing--maybe--but I'm not going to buy jeans until I can at least buy a size 10, and I would really be happy to be buying a size 8.