I mined 12 BTC from my gaming computer dual-booting between Linux/Windows that I also used for SETI@Home and Folding@Home, I ran the miner just for fun as I thought it was another distributed system doing computations and was fascinated by that concept at the time.

They were lost when I had to re-install Windows to play games and formatted the whole hard drive. I don't think much about it because it's so long ago but I'd have enough money to start realistically considering to retire...