I had several treasure maps from thieves' troves. I didn't bother to launder them; they're usable.
I search for the chests, so I'd looked for one for a long time over different days.
Recently, I found I had an old quest that needed me to break into someone's house, which I normally don't do. A guard saw me. Easy option - why not pay the bounty, I don't think I have any stolen goods to be confiscated. Today, I was back in the zone and finally think I found the treasure chest location. I go to look at the map.
I finally realized why it wasn't in my inventory. It's all too easy to forget stolen items you have if you pay bounty, and they can't be recovered.