Hey Jan,
Thanks for the question and for the nice words! There's really no "X hours" that apply here, as every person is different. But the "how" is really very simple and reliable across the board:
1. Find a resource to learn from (e.g., my books!).
2. Take notes as you read.
3. Try. Try. Try.
It's a known thing about the mind that you'll learn better if you take notes, even if you don't ever refer to them. Not just highlight, but actually write down key thoughts somewhere. And if you refer to them later, all the better.
But, no matter how much you read--either in time or n