Lost in my own head

Do you have hear yourself talking and have to stop in your head because while what you said is accurate your not really sure how you knew the answer? I feel like that a lot at work. It’s almost like I am making stuff up but I really do know what I am talking about I am just sure how I know what I know. It’s a very odd feeling. I wonder if other people do that. I mean do surgeons get in the middle of surgery and think “Hmm, how do I know how to remove this appendix? I know how, but how do I know how?” That’s kind of a scary thought right?