I once won a stereo and a complete collection of kids’ tapes, but that was because I had really, really wanted to attend the auction and had already sent in my selections but at the last minute couldn’t go and for once, I didn’t complain. It was a reward for good behavior.
Once I went to an auction and bought a lot of tickets. The tickets were the two-part perforated ones, and the top part said “Keep This Part”–so I did. After putting the other halves into the boxes and leaving, I thought, “Gee, didn’t I buy more tickets than that?” It didn’t sink in until two blocks later that one was NOT supposed to keep the other half! Won some life experience, there. 🙂 (This could go in the “Embarrassing Mistakes” thread, if there is one.)