Absolutely agree. The best and most creative environments I have worked in have been full of people who you could turn to and say "What if we did X?", and they

Absolutely agree. The best and most creative environments I have worked in have been full of people who you could turn to and say "What if we did X?", and they would immediately come up with reasons that X would fail or be impossible. If your idea hadn't been absolutely annihilated after 5 or 10 minutes of this, it was probably pretty decent.