Death

You know how they always say that near-death experiences teach you to appreciate the people around you a lot better? You know how the characters often depicted tend to be female--and hence this display of vulnerability becomes so much more endearing?

It often really doesn't work like that in the real-world. People get weird-ed out by such attention. Especially if you're a boy, I'd think everything becomes laced with intention and agenda. If you were given 10 days to live, you get to show appreciation and then go out in a brilliant emotional blaze. But when you go around saying your goodbyes and then life continues to move ahead, it can only get awkward.

It reaches the point whereby the best way to show appreciation is to just disappear from their lives entirely. Because if death doesn't come to provide the fairy-tale ending, then that's the best way to simulate a similar result.

Movies clearly often end too early.