This is an excerpt from a New In Chess interview in 2011 with economist and Grandmaster Ken Rogoff. In 1969, his play impressed Bobby Fischer enough to annotate one of his games for Boy’s Life magazine (the article can be found here).
“A very important part in chess is figuring out your mistakes and how to improve and it’s very painful. Because, let’s face it, it’s much more fun to play over your wins than the losses. And yeah, you just have to play over your losses again and again and again.
I remember meeting Bobby Fischer when I was playing in the US Junior Championship in New York in 1969. He had been having problems with rook and pawn endings and he basically finally said, OK, this stops here, this isn’t going to happen again. And he was spending all his time on rook and pawn endings. And indeed, I think it was against Geller that he won a rook and pawn ending after that, you couldn’t have imagined that before.
I think that takes really steel will and most people don’t have it. Most people lose the same game again and again and again. They don’t realize that they are losing the same game again. The real top players have that ability to try to suffer repeatedly through the same defeat and learn from it.”