I assume that people come to the gambling industry as inexperienced people. And in the process of their activities, they gradually learn from their mistakes. Unfortunately, some of these mistakes are dramatic and cause us quite serious psychological trauma. As a rule, this is due to gross errors and stupid persistent beliefs that push us to the edge of the financial abyss.
And I believe that most gamblers never learn anything. We are talking "in the global sense", and not about the rules of the game or the strategy to win in these games.So, how much did your mistakes cost?
In my case it was cheap, but this experience was enough for me.Did they cause you a serious psychological blow?
I don't think so, but it allowed me to "face the truth."What were your mistakes, did you learn from these mistakes and do you apply this knowledge in practice now?
My biggest mistake was believing that I had enough "luck" to win. I learned not to rely on luck and to chase "easy and quick" money. Oh yeah. I apply this knowledge - I try to stay away from gambling. 
Were these mistakes simply painful, dramatic or catastrophic?
I would call these mistakes instructive.