In tennis you move a lot. Golf you dont. In tennis, you can have a bad half-hour, but you cant in golf. You can lose the first set in tennis and still win.
What I like about golf is there are no bad calls.
I certainly don't lose any sleep if I lose a tennis match.
I just travel all the time.
Once you win, you have no doubt that you can win. So you have gone through it once, and you can do it again.
People may say I developed an iron will, but what really happened is that I made myself much fitter. I think an iron will is always supported by fitness.