Here's a quote from the middle of an entry about why he is alive, which in a word, is "insulin":
Optimism is a terrible evil, one of the greatest ever, imho. Like religion or shame. It is a destructive creation meant to enslave. Its very hard to explain why unless you're a serious pessimist like me. Optimism has positive results, but the negative ones are maddeningly squashed and ignored. People don't learn when they're optimists. They just keep thrashing around until they're dead. And usually, after they've infected more idiots with optimism so they'll die too. Peasants aren't optimists, they're just realistic about their odds of survival and accept an early death as the cost of being alive at all. If we were less greedy for comforts, and less optimistic, we'd have avoided the pitfalls that have already doomed our civilization, and will send people like me off to a painful death.