Super helpful thanks. I've also read a lot about how mentoring should be mentee-initiated. Is there anything that I can do as a mentee that can also help the mentor be a better mentor?
Well, speaking personally, it's very helpful if the mentee is willing to say things like "I don't understand that, please explain it in a different way." Often I think people just keep quiet, out of shyness or politeness, or not wanting to appear dumb. But the moment you've lost the thread of what's happening, you're both just wasting your time.
A good mentor can pick this up, and is constantly checking to see if the mentee is really understanding, or whether they're just saying "Uh-huh". But it's a two-way process. Sometimes you will genuinely struggle to get something, and that's okay—everybody finds different things easy or difficult. If this is happening, just say "Sorry, I'm having trouble with this. Can you go through it again?" The mentor absolutely won't mind doing this. They're not here to look smart, they're here to help you learn something, and until that's happened, they haven't done their job. [If they do mind, get another mentor.]