Upload & Sell: Off
I haven't lost anything noticeable (maybe a lens cap or gel?).
I have an assistant though, so that's part of their job, to keep track of my stuff. Part of the reason I hired someone was I was constantly leaving stuff all over the place. One of my first assistants once asked "where's that 50L you had?" and I'm like "I don't know... check those bushes over there". Sure enough, I left it in a bush by the ceremony. I've also left stuff sitting in the middle of the road, in church pews, under tables... So if it wasn't for my assistant, I would probably be missing all sorts of stuff.