I was responding particularly to:
> it is probably a warning sign if everyone thinks your idea is good straight away as then it is likely that someone else has had it and is working on it, or there is some fundamental flaw that you have missed.
I can't get to the original at the moment so my comment is specific to this comment thread's context.
I'll just leave my favorite economics joke:
Two economists were walking down the sidewalk discussing their recent research when one looks down and sees a $20 bill.
"Look, a $20!" says one, slowing to bend down and retrieve it.
"Impossible," replied the second, stopping the first mid-bend, "if there was a $20 bill on the ground, someone would have already found it and picked it up."