I had a friend who was so talented in basketball, a really really great dribbler and just a cool guy, smart, you name it. But he had this thing about "why do you have to waste time living?". So he kept on telling me how he wants to commit suicide at one point, soon that is. And I was trying to see why (first I thought he was joking) and he was telling me he sees nothing exciting in living. So I was like "hey man, but you play ball, you listen to music, you do this you do that - these are good reasons to live for and you wouldn't do all that if you weren't passionate about them in the first place".
So I tried my best to make him think otherwise. And I haven't really talked too much to him about this because I didn't REALLY thought he was serious. But after a while from that discussion (half a year or so) he threw himself off the top of his 10 story building and killed himself. I'll always have all this story with me ^^^. But IN A WAY - it was expected to happen. Thinking back to his demeanor when he was telling all that stuff - it should've been obvious he was going to do it.
The idea is that not everybody falls into the "same general way of thinking". I don't know if it's something to be judgemental or superior about, I don't think so, but it is what it is.