I took a training class this week on Security and Active Directory.
The most useful things I learned have nothing to do with AD.
I learned that it is common, but not "normal", to feel grossly incompetent in your chosen field. This is particularly the case if the if the work comes easily to you. It's called Impostor Syndrome. There is a corollary principal called the Dunning Kruger effect. This states that you are most likely to be competent in a field when you feel most incompetent. I.e. It is human nature to underestimate your strengths and overestimate your weaknesses.
Thanks brain. Let's see what we can do about that, K?