Not really, to have an impact a teacher needs 1-on-1 time with a student, otherwise the kid might as well use electronic material without any teacher at all.
Sure, but the bigger differences are usually made while people are younger. It gives them more time to take advantage of them and grow with them.
*addendum: In short, if they can appreciate the university lecture, odds are they've already had some good teachers, and/or managed to work around the poor ones.
Yes, compared to early life 1-on-1 teachers online university lecturers make a small difference. Compared to baseball players they make a large difference.
also, the impact of a teacher on a single child can be a lot greater than the impact of a celebrity on a single person. this is not to say that the reverse is not also true, especially if the celebrity is inspiring a young musician or sports star. ultimately, this is entirely subjective. what does "impact" mean, anyway ;-)
