People are remarkably bad at remembering long lists of goals. I learned this at a professional level when trying to get my high-performance coaching clients to stay on track; the longer their lists of to-dos and goals, the more overwhelmed and off-track they got. Clarity comes with simplicity.
To be successful in anything, you have to have a passion for it, and that leads to being enthusiastic and demanding. I didn't have it for history. So I wouldn't have been a good teacher in that area. But I had it for basketball. And that's what coaching is at every level: it's about teaching.