The bell rings, and I'm faced with a class just sitting there, looking at me expectantly. The room is silent.
I wasn't quite sure what to do. Such things don't happen. A sub in the room? Chaos reigns. They don't sit there and wait for me to speak.
It's much more common for me to have to ask for the class's attention, wait, ask for attention again, and then get most of the rumbling to stop. I'm used to talking over students while explaining the assignment. I'm used to having several students later ask what they're supposed to do because they weren't listening the first time (to which I usually reply that they should have been paying attention when I explained).
This group? All rapt attention as soon as the period started. And then they got right to work!
These are the good days. These are the teachers that I always agree to sub for.