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!
It's hard to learn from your mistakes if you will not accept that you have done it wrong. The first thing that we must do is to accept that we lost and we did commit a mistake. If you are too rough and hard to accept those mistakes you've done, you'll find it hard to learn those lessons that you should learn already when you lose. I did learned from my gambling mistakes and one thing that I've learned is that don't be too greedy when you are in the casino.