Staying in your lane.

Ben Carson, by all accounts, is a world renowned, brilliant, exceptional neurosurgeon. He was considered at or near the top of his field, and it was a difficult field. He worked hard for it, he excelled, I couldn't do what he did, and it's deserving of respect.

He was an absolute, complete and utter moron on public policy, economics, and history when he ran for President, and that was apparent every time he opened his mouth to speak on any of those non-medical topics.

Specialization of knowledge has been a beneficial thing for humanity, and you can't be an expert in everything. Sometimes it pays to stay in your lane, shut up when it comes to what you haven't studied, and focus on what you're actually good at before you embarrass yourself.