From a WSJ interview with Chipotle founder Steve Ells:
Q. What advice do you give to other entrepreneurs starting out?
A. So many people told me it was not a good idea to a start a restaurant, especially a fast-food restaurant. There was so much wrong with it – it was too spicy; everything was done by hand, from scratch. Everything was wrong. But that’s why customers liked it; it’s different, in the right way. If you have an idea, just go for it. If everybody is telling you that it’s wrong, maybe that’s an indication that it’s an original idea.