Falling asleep is really cool.

If you pay attention, you can watch your brain shut down. (or, better metaphor, "suspend", or more appropriately "do a bunch of things differently than it does when you're awake.") How neat is that?

You're having a train of thought and then you realize you can't remember what you were thinking about literally seconds ago. Not a clue. And then you're on to the next topic.

Also, the next topic is often really goofy. Leaps that you wouldn't ever think of when you're awake. Yeah, every so often someone discovers the benzene ring, but more often you just come up with a pretty entertaining nonsense story, and that's cool too.

You can see all this happening! (Until, all of a sudden, you can't anymore.) I think that's cool.