I usually think of each poker game as one of many that in the longterm will be profitable for me, but when I win a lot in a short amount of time (I play sngs) I want to quit because I am already at or ahead the target i've set for myself. When I lose a lot early on I also like to quit because I tell myself I am not playing as well as I should be (which is sometimes true). I don't want to think this way, but find it hard not to. Anyone else have this problem or some sort of way to get your mind away from this type of thinking?

The problem isn't knowing what to do, it's the execution.