Hazel: Can I ask a stupid question?
Death: Sure. Ask away.
Hazel: It's sort of more that one question. But. Look. Um, why do we hurt? Why do we die? Why isn't life good all the time? Why isn't it fair?
Death: Those aren't stupid questions, Hazel. For some people they're the only questions that matter.
Hazel: Does that mean you won't answer them?
Death: Sure, I'll answer. But it's kind of a big subject, and it's got lots of answers. And the answers don't really mean anything.. They aren't stupid questions but they could just as well be "When is purple?" or "Why does Thursday?", if you see what I mean...
Hazel: Not really.
Death: Well.
I think some of it is probably contrasts. Light and Shadow.
If you never had bad times, how would you know you had the good times?
But some of it is just: If you are going to be human, then there are loads of things that come with it. Eyes, a heart, days and life.
It's the moments that illuminate it, though. The times you don't see when you're having them...
They make the rest of it matter.

Death: The Time of Your Life ~ Neil Gaiman