When we argue for our limitations, we get to keep them.
The value of action is that we make mistakes; mistakes show us what we need to learn.
All the things you think you should have done that you didn't do, and all of the things that you shouldn't have done, accept them. You did (or did not) do them. That's reality. That's happened. No changing the past.
Your Master Teacher knows all you need to learn, the perfect timing for your learning it, and the ideal way of teaching it to you. You don't create a Master Teacher -- that's already been done. You discover your Master Teacher.