Are You Taller Than a Fifth Grader?

I arrived in the lunch room at the same time as the entire fifth grade yesterday. One of the teaching assistants was controlling the flow of students to the circle serve. I spotted the plate I wanted, skipped up to the circle serve, snatched it up, and walked by the teaching assistant. As I passed him he put his hand on my shoulder to stop me. Then he turned to look at me and said, "Oh. You're okay." He thought I was a fifth grader who had slipped by him.