I, too, have placed things for me to find when I need them or make it easier to find until I need them. Then it's the black hole until I don't need. Thankfully, I usually haven't bought a replacement.
The times it really bugs me is when I buy a book, magazine, or tool that I really like, either online or at a store. and guess what I already had it!
Luckily, I haven't done it for a while.