Mentors and Tyrants: You Have to Let the Students Go.
That invitation was important to me - more important than I would have otherwise guessed. I've been at (and spoken in front of) larger and more "prestigious" audiences than I will at my library.
But this is my town. And they're actively seeking out my expertise. Which is kind of awesome.
I like talking in front of people, and sharing what I know. It's one of the reasons I enjoy panels so much at conventions, and have a really hard time staying in the dealer's room. I've had people call me their "mentor" - which is both immensely gratifying... and immensely frightening.
The constant danger when teaching - whether in a classroom, at a talk, or as someone's mentor - is the echo chamber. Your students (no matter how unofficial) start parroting back what you want to hear. You reward and punish based on how closely they adhere to your gospel. You start ostracizing those who challenge, those who do things differently, those who have different goals, those who question you.
When you do those things, you stop being a teacher and start being a tyrant.
There are a few "gurus" that I will point people toward. Seth Godin consistently delivers up platform-agnostic insights into the nature of business. Gary Vaynerchuck's Crush It! also delivers inspiration and insight without dictating a specific path. Evo Terra doesn't suffer fools gladly... but he isn't threatened by a different point of view.
There are hundreds - millions - of wanna-be mentors out there. And I believe there is one essential1 quality for someone to be a good mentor:
They have to know when to let go of their followers and their ideology.
When you see someone who seems like they might be a good teacher, find out where their former students (or mentees) are. See if they are succeeding, if they are still supported by this mentor, even after they've parted ways. That's a good sign.
And if they're still helping to prop up the mentor themselves... well. You get the idea.
1 Essential - meaning that without that quality, they cannot be a good mentor. That quality by itself is not sufficient to being a good mentor, though.