You will not be so flattered when you realize they've captured 90% of your potential paying users.
50 people - heck even 10 - who think my product is worth using and I'm happy. That's how low my expectations are, just to keep myself sane :)
(I'm obv. not counting on this product making me a full-time income. I'm doing it for the experience and to get a feel for the industry.)
We'll see though, and you are right that keeping low expectations is a key.