Very true. No matter how involved we get in projects (personal or business) we all need the ability to take a step back and view the larger picture.
Outside review, critique (good or bad) is essential to make adjustments and moving forward. Communication is key. If we shut out those channels we are often blind to our own mistakes or their impacts on others. That whole "not seeing the forest for the trees" thing.
Many times our own ideas are not the best, we have to put ego aside and redirect own our efforts to those ideas "we know" are better and nurture those ideas for the better good of the community.