This happens approximately with everyone. When I was new in crypto and didn't have any experience, I made many wrong decisions, and now I am regretting for those decisions. I got 5x profit from a coin but I didn't sell at that time and now I am at a big loss 
. So I have learned a lot from my mistakes.
Actually this is not a mistake but like a disease that is experienced by almost all crypto players. Greed and lack of self-control to take profit in the right position. People who are technically good sometimes still get stuck with TA that they make themselves even though they already know which area to take profit but they still want gets more. So I have learned a lot from my mistakes.