Unless we are hooked-up to an old fashion party-line where one landline served multiple parties, it is unlikely we are hearing all communications and perspectives. One of the great joys is meeting another person who sees the world in a profoundly different manner and alters our world view. It may be as simple suggestion that changes a subtle routine or it might be as grand as reformatting a universal truth.
The mindset that we have heard it all is limiting. If we gather with like-minded people to discuss new ways if thinking, we miss insights that individuals with weak ties to our cause might offer.
Sometimes we need to look at our inputs before we can adjust our output.