I completely agree that everybody needs to do what makes them happy - though I think that "happiness" is relative - many people would be happier with more means available to them... others might not be. No matter what 95NSXT does, he will undoubtably feel the "what if" urge at some point in his life - I think more happiness can be generated when we throw caution to the wind and follow that urge.
In my limited experience, I've noticed that most of my friends are relatively happy with the middle-class status quo. That is great for them, but then I hear them saying, "I wish I had this or that," or "I'll do that when I win the lotto," or some other generic phrase pointing to a desire to be or have more than their current situation. It is human nature to grow and desire bigger/better things and while complacency may beget comfort, it never leads us to our full potential. I'm not saying that everybody should do their own thing, but be a superstar in your life (i.e. do not settle for less if you want more).
Also note that health, wealth, and happiness are not mutually exclusive. While I am certainly not worth $600M, I do have a couple modest M's below my belt... I am not overworked, I am in extremely good health (I was even a fitness model in college), and I have a beautiful wife whom I love very deeply. I have nothing but gratitude for the things I have achieved and for life itself. I am fortunate in that my mind is not troubled with the mundane, but rather by the passion to reach my full potential... It is no crime for me to want everybody to feel that way.