This is a very true statement. The danger that I've seen is so often people think, "My idea seems bad to most people, ergo it must be good!"
How do you separate the seemingly bad from the actual bad? Figure _that_ out, and you'll make something of yourself.
This is basically the business YC is in. The short answer is: practice. One day I'll try writing down the long answer.
I generally shy away from the numbered list blog format, but this is a classic read IMO.
"We are all agreed that your theory is crazy. The question which divides us is whether it is crazy enough to have a chance of being correct. My own feeling is that it is not crazy enough."
Try it and find out.