When I was a college student, I had a part time job as a delivery driver for a florist. I know what you are thinking, my ogre uncle could never have worked in a flower shop.
Actually, it was a great job. You spent most of your time driving around listening to tunes, and sometimes even received a tip for your work. The hardest days were Mother's Day, Easter, and especially Valentine's Day. You were constantly on the road with little breaks (you would place your lunch order with the shop before your morning run, pick it up with your afternoon run, and eat on the road). You would have to remember and coordinate your route so you didn't have to back track, remember the address and how to get there, all while keeping your eyes on the road knowing the name of your employer was emblazoned across the van.
It may not sound tiring, but mental labor can be exhausting, especially when you don't want to get into an accident. I give a lot of credit to long distance truckers.
The year before I married your aunt, I rented a house with a few guys. One of them used to get on me about taking naps after I got home from work.
"How can you be so tired, you're a teacher."
"Teaching is like driving a car.
Taking your eyes off the road can lead to tragedy."
Mental exhaustion is real. When you are driving your are constantly looking at what is in front of you, on the sides, behind you, while keeping your destination in focus for what could be hours. When you are teaching you are:
1) thinking about your lesson
2) thinking about what you are going to say next
3) listening to your students
4) answering and asking questions
5) maintaining classroom control
6) all while making sure the 20 or so students in front of you are listening and not, texting on their cell phone, stabbing their neighbor with a pencil, sticking gum under the desk, among many other crazy things that could happen.
Daydreaming as a teacher could cause terrible consequences.
-or at the least, embarrassing ones-
A few years after I married your aunt, I ran into my former roommate. He had decided to try change careers and was currently a student teacher. He recalled what I had told him and he said,
"You were so right, teaching can be exhausting."
And since that day I have only grown in pride for what YOU have accomplished.