I couldn't think of anything that didn't sound trite when I first filled out the form, so I left it blank and decided to come back to it later.

(As far as I'm concerned it's a long shot. I don't think my idea and my goals for my business line up that well with what YC is really looking for, based on what they've done in the past. So I filled out the form more for myself than for them.)

But then I thought of the best answer to that question -- the most personally meaningful thing I've discovered, something that I don't think anyone else has ever noticed -- over the weekend, and only realized this morning that the deadline had whooshed right by while I was sleeping.

Oops.