And despite the great story this image tells, it also isn't universally true - most of the successful products I've worked on never went that deep into despair. We fixed a problem, built something that worked, got customers, and went fairly quickly from idea to the "OK, but it still sucks" point. Maybe we never hit the height of the image, but we built respectable products that were profitable and fun to work on.

Sometimes that valley of despair is something to work through... but just as often, the idea just isn't that great. Telling the difference between the two is the key.