Becoming mentally strong

[Popinjay]

I heard the quote the other day that Tiger Woods was the most mentally strong athlete in all of sports. Maybe he is in the world of sports but some poker players have to rival him. Well maybe not. When I see a lot of the top pros on TV it really seems like the beats still affect them.

So how does one become mentally strong? So much so that one never loses their cool whether it's playing golf or playing poker. Perhaps to the extreme that when your opponent hits runner runner in a 50BB pot you don't feel a thing.

I think it's interesting to look at very mentally strong people. Two people come to my mind, Zen masters and elite intelligence agents. The Zen masters just have that cool way about them, and intelligence agents are able to withstand the most intense interrogations (at least according to movies).

So how is incredible mental strength acquired?