Anand was recently quoted as saying that it was nice to play without any opening preparation before the Mainz 360 tournament. This shows that studying endless lines of opening theory is regarded as work, but to reach such a level of chess mastery one must love the game.
Korchnoi is another example. How many of us would prefer lounging around the pool on a nice summer day when in our 70's? Apparently not Korchnoi. Based on this I am of the opinion that one must enjoy what they do to be able to not only reach the top, but to stay there.
does anyone out there think grand masters still enjoy the game as much as players like me who are much less talented and have to think about almost every move or do you think that much of the fun is lost when you are just responding to known positions