Losing
Losing is really painful for some of us for example I just lost 3 of my games. Although I know my mistakes I naturally build up with anger but eventually I realize there are plenty of other games and it is no big deal. For the majority though you'll challenge your opponent for as many times as it takes to try and get their King in checkmate. Losing is not easy but look and see your opponent's records it's not as if they're perfect either. I mean it is just an off day. I tend to think of it as building on your mistakes do not let a loss get you down. Build on your mistakes and you'll be less likely to get another one of those days again type scenarios. I lost three games but it did not stop me from continuing on. It is just a minor set back and next time I'll win and again and again.