There are so many and you have no way to know if you've already used them or not. It would be nice if they just disappeared after use.
I find that my keys disappear quite happily. They are usually later found in little-used coat pockets, under paperwork or casually dumped on the kitchen side.
Maybe Larian could add a quality to keys that makes them disappear and then randomly turn up in someone's inventory? On second thoughts, maybe not though.
