You have to be OK with yourself and be willing to speak freely with your students. They know it and will call you down for it. And then there are the other teachers that you work with. Students compare you with them and them with you. You have to be your own person and like yourself to take that.
Some teachers are lazy.
They just stand up in front of their classes and talk. They seem to think they know what students need to learn. I would rather develop the confidence in you that you know what you need to learn. I like active learners. I like responsible learners.