I once had a big ego. I had a hard time separating my design work from my competitiveness and personal drive. And I worked at a place where you had to be that way to survive the constant barrage of "this is not good enough" and lack of gratitude. It was King of the Mountain with the king already established and the rest of us kicking each other to rise. But I kept playing, trying different ways up the hill. It nearly broke my interest in design.
Now? I have a little mantra of confidence without ego. I have separated the two so that my confidence and drive can be benevolent and a guiding path for collaborators. My ego created rigidity in my decision making, while my confidence affords opportunities to try things that aren't clearcut.
When a cohort asks me to change something, I no longer think of it in terms of my vision versus theirs. I first think if there are any usability or systemic reasons that it can't be done. If there aren't and yet I still don't feel right about the request, I ask for more information and try to reach the root of the challenge they are having. If that root challenge is something previously undiscovered, then I ask their permission to solve the root problem in a number of ways. Otherwise, I generally say, "Sure! Let's test it out!"