Sometimes, being too confident can just make us lose the money that we should have used to stake on other games. It has happened to me many times, even yesterday, I was very confident on my parlay of 8 legs which the rest of the 7 games was successful but lecce didn't give Bologna 1909 any chance at all, it was tough game that ended in an unexpected draw.
This is very correct, it's okay to be confident sometimes but it shouldn't be all the time because eventually you are still going to loose at some point and also win but what matters is when you win is it enough to make up and do you have a strategy that helps you loose less and win more?