1. Nobody wants to admit they don’t know. Not in front of you, certainly not in front of their peers. Related, almost nobody that needs to goes to office hours.
2. Teaching the right way to do something is the minimum. Teaching how to avoid all traps; the appealing and intuitive but incorrect or inefficient ways to do something is better. Students will amaze you with all the ways there are to fail to solve a problem.
3. There may be steps you are not articulating, because you're not aware you're doing them. If one student gets it wrong, it's probably them, if most of them get it wrong, it’s probably you. As a new teacher, you will learn as much from their struggles as they do.
4. Related, there are steps you have mastered, like a tightrope walker, than can not be immediately emulated, despite the apparent simplicity of the instructions.
5. You chose this material, they may not have.
6. Related, you want to share the material and your enthusiasm with them, which is good, but they may only want to get the minimum they need to get by.
7. As a teacher, despite the lack of respect you may feel, they see you as an authority figure. You are the institution. You are not one of them, even if you are. They don't want to see you in the hall or at the grocery store; it does not matter your respective ages.