I have always ended up learning from my mistakes, because in my personal situation, those mistakes which involve losing money because sport betting involve some psychological taxation. When I lose (regardless of the amount) I feel bad because in this country and with the economical situation we are going through, there are many chances for one to waste money on casinos.
I have learnt to manage my bankroll, stay away from minor leagues and only to bet when I have a combo of reasoning and also some gut feeling/hunch which tells me I am supposed to lean towards a direction or the opposite one. For some reason, I have also learnt it is better to follow one's instinct instead of depending on the signals or advices of others.