It's very hard to learn form gambling mistakes. First of all you have to realize you are making a mistake and not just luck. Most of gamblers blame the luck and that is all for them!
To bad for those who can't accept their mistakes because they can't move forward and just have self pity all the time and just even end up broke. We're all humans and making mistakes is just usual so learn from it but what's unusual is when you always commit the same mistakes all over again. It's different story tho.
Making mistake is normal but making it multiple times is too much to handle, we should learn from mistake, if we know it's hard to win or earn in gambling better not use it as a way to earn, make it as activity for chill and feel thrilled without expecting anything in return just a mere of enjoyment, but only few people realize it, and most who realized it were already came into that point of too much greed and addiction. Always have limits and control in every decisions made.