Aviation
At my first duty assignment, I had to teach a class to pilots senior to me. Before I did, a seasoned instructor told me I would get part of it wrong, and that this was the point.
Do not repeat the mistakes others have already made. Make new ones, the kind everyone learns from. That idea became the backbone of how I work, and later the title of my book.
Flying runs on what the FAA calls aeronautical decision making, the discipline of judging well under uncertainty. It rests on two habits I have carried ever since. First, ownership: at 100 feet there is no committee, so you make the call and answer for it. Second, fundamentals over automation. Follow only the magenta line the instruments draw and you have nothing when it fails; know the first principles underneath it and you can still fly. I lead on the same two things, judgment and fundamentals, not the script.
It settled into the way I lead: set a clear direction, align the resources behind it, move people to act, and answer for the result. And I keep the instructor's lesson inside it, building teams that are free to make new mistakes rather than bury them.
Judgment is not the absence of error. It is knowing the fundamentals well enough to act under pressure, and standing behind what follows.