[peteforde]

I accept that I should have arrived at a less-lazy way of describing the feeling I get when I am able to detach myself from a pet-favourite idea long enough to see its flaws.

It's been my repeated experience that most people are unable to tell the difference between a good idea and a total dud. Certainly feedback helps, but I would also suggest that most people are trained from birth to only say things that they believe you want to hear. The people you know are almost unable to give unbiased feedback, and they can't help it. They don't want to disappoint you.

Learning how to effectively find flaws in your own idea (boredom is an ineffective but common approach) is an incredibly valuable skill. A bad idea well-executed is still bad.