I once saw mine in his car while I was walking to class. I was trying to cross in front of a street and he happened to be the person who let me go...I subconsciously registered that I recognized whoever was in the car, so there was this awkward moment of me staring too long to figure out who it was. We both recognized each other at pretty much the same time and had an awkward "Oh, I know you, hi." moment. Did I mention it was awkward?
We only bumped into each other one other time on campus and I wanted to disappear. Ts don't exist outside of their office...It's like seeing an alien.