I've had the pleasure of having great mentors in my business career. I'd seek them out whenever possible.
One of the best was not a charismatic guy at all but a quiet, intellectual, operations, and financially focused executive.
He'd take time with me to hear me out and provide sound advice. He never judged me or criticized my immaturity at any time.
We still stay in touch from time to time even though he's retired.
I learned more about leadership from him than any course I've taken.
I don't discredit courses or books - they're valuable. But they can't replace the value of a mentor, coach, or just someone to talk to.