The worst decision i ever made with ny bitcoin is to put all of ot on gambling but luckily at that time i am not earning that much than now and luckily i also learned from that mistake
That was not a mistake. You've chosen to put it all out of your own will. Then you will call it a mistake when you lose? So what if you won?
A better term would be a "lesson".
Sometimes we do the things which we are not supposed to do but we don't realize it that time so later on we say that we did a mistake by doing that thing, so we can actually call it a mistake though it teaches you a lesson but at the end it was a mistake done by you.