Arm rest

On the airplane coming home from Texas* on New Year's Day:

Beatrice: What's this?

Summer: An arm rest.

Beatrice sets her arm down on the arm rest and holds it there very still for at least a minute.

Beatrice: I'm resting my arm.

Another minute passes. Beatrice lifts her arm.

Beatrice: Now my arm is awake!

*About which a long entry is coming tomorrow.