#TDD is about practice, "instead of reading the menu you eat the food".
It's not about 'book learning', it is experiential. You can't study your way to expertise, you have to practice.
The practice changes you, changes your mind, changes your way of working, changes the way you think. It is transformative.
You don't need a mentor or coach for this, I didn't have one, but it does make it a lot quicker and easier to achieve competance.