There are many things that I will never forget losing. My 2 biggest fails:
1. CLEAR Buffet B12 with copper keys. Extremely rare. Sold for $200 about 10 years ago. I was a poor kid and couldn't afford it. Probably could sell for over a thousand now.
2. MCINTYRE SYSTEM alto clarinet. I've only ever seen two of these. Sold for $400. Probably priceless.