Have you ever been in a situation where you took a big loss. clearly because of your own mistake but instead of owning it, you ended up blaming the casino? Maybe made some excuses just to avoid feeling stupid?..
This is a common practice, when you win, you believe that it's all due to your own strategy, and when you lose, a person usually looks for reasons elsewhere, without acknowledging the fact that he made the decision himself and this wrong decision led to a loss.