I am a teacher: I have raised children which is mainly teaching them how to be a human being by teaching them all the behaviors (including speech) we expect from fellow human beings.
I learn from many people, including Guru's Handbook, Chiron, and too many others to list. They're not all intentionally teaching, but I can learn nonetheless.
Not all students learn what the teacher thinks he's teaching.
Talking about yourself isn't teaching, it's establishing your authority to teach. How much of that do you need to do? Depends on the student; I was completely turned off by the pages and pages of appeal to authority at the beginning of Gavin de Becker's The Gift of Fear (which I strongly recommend), because I already believed he had knowledge I wanted and I wished he would just get to it. But many students need proof of mastery from a teacher before they'll engage with the material enough to learn.
We are each role models whether we like it or not, there's no consent involved here. Students *will* learn from what you do whether it's to hermit yourself away from community or open a school, whether you're a role model for useful behavior or for destructive behavior. Your agency has scope in the field of the nature of what you will teach, what lessons are available from you.