It happen to me when I went to buy my car.
Izzy, are you sure that it wasn't actually your 10th cousin's best friend's girlfriend's nephew's neighbor giving you a thumbs down reference?
Just kidding. I've heard the "too many credit checks" advice, too. But as a point of clarification, you can check your own credit history as much as you want without it counting against you. Just be careful of how many businesses you let run your credit in a relatively short period of time.