Broad example:
Let's say you play 10 different pots and they all contain 10 BBs each. If you call 2nd pair on the river everytime and lose the first 9, you've lost 9BBs. If you pick up the 10th pot, you've won 10BBs and your net in the 10 pots is one big bet.
Losing 9 hands in a row on the river and your perception is going to be that your losing your ass. However, the 10th pot makes up for it and you've won. You have to be able to put it into perspective. Trust me, Kurn is no fool.
And Kurn already posted!!!!!!