I've sold tons of Bitcoin at around $200 and also sold even more ETH at around $5-$10 a coin. I sold because at the time it looked like a fair price and I needed to money to pay for electricity and buy more GPUs.

Yes if I've held till now I would definately get much more for it but you can't predict the future. At the time BTC when it traded around $200 it looked like it would break $200 support and head into the $100 area and maybe even double digits. And ETH at the time of the DAO hack was not looking good either, and it could of went back to $1 ETH a coin.

Sure if I knew what the future would bring I've obviously would of held but I didn't. Same with you selling at $3000. You said you knew it was going to go up but how sure were you? Not very. It could of went to $2000 then $1000 and you wouldn't be able to buy food like you've meantioned.