[Michael]

maybe he felt something was very wrong in his life, no matter what great things there were, something was wrong or missing and perhaps he felt he couldn't deal with it or wasn't stronge enough to.

or maybe he was depressed. lots of people who have depression know just how to mask their condition to others. if he was sick emotionally and/or mentally, and everyone around him thought he was happy and normal, he obviously never recieved help. which is bad of course cuz the condition builds up over time and gets worse.