With something like Dropbox, it was immediately like, 'Wow, this is literally something that anyone with an Internet connection could use.' Everyone needs something like this; they just don't realize it yet.
You need that hunger no matter what, because eventually the honeymoon period wears off. Somewhere between printing your business cards that say 'founder' on them and everything else you have to do, you realize, 'Oh, actually this is a ton of work.'