Want to learn any serious skill the serious way? You’ll pursue some kind of apprenticeship, or some kind of learning under a master.
But wanting to learn a skill is one thing. Getting (and deserving) a good master is another, and it only comes to the people who are already doing the work to learn.
Only the man who teaches himself is interested enough to be taught. If he will pursue a skill in the rare free times of his life, he has enough passion to want to soak in a master’s wisdom.
Only the man who is teaching himself is disciplined enough to take advantage of a teacher. He is demonstrating the work ethic of someone who is self-motivated.
These truths are useful both for the current apprentice and for the apprentice-to-be. If you would get a master, self-teach also to be worthy of one. If you have a master, self-teach also to ensure you are learning what needs to be learned from the master.