There are two kind of mistake I can figure out from human life in whatever you do. Avoidable mistakes and unavoidable mistakes. And those two elements of mistakes can also be found in gambling. The avoidable mistakes are those mistakes as a gambler you know that can be avoided. Example you know that a particular team win in the match and you still play against the team. Like PSG vs Chelsea. That was an avoidable loss for the side of the gambler. And many gamblers loss the game and where in sorrow and painful.
And unavoidable mistakes are those games you bet on that you don't know which team would win and you play base on the previous performance of the two teams.