I just heard someone say that if you aren't a teacher, you can't substitute a classroom.

A high school principal said something along the lines of "If you're an orthodontist, you can't come sub in my classroom. You don't have the training to teach them, and it's not your job to teach them. How would you like it if I came in your office and told you how to put brackets on someone's teeth?"<br><br>I thought this was a great way of putting this, and I agree with it... but I'm wondering how you all feel about this. Do you think that's a bit dramatic or arrogant, or do you feel that way too?