One of my first times in a nightclub I had my driver's license out of my wallet to give to the bouncer on the way in and I forgot to put it back. At some point it must have slipped out when I was getting money or something because when I got home I realised it was gone. Fast forward through 2-3 days of worrying I got a letter and inside it was my driver's license with a note saying "Found your license on the floor of (club name), be more careful next time!". Serious relief and I couldn't believe someone had been decent enough to send it back to me