Once when I was teaching 10th grade American lit, I came to class just emotionally empty for whatever personal reason or non-reason, wondering how I'd ever beam the appropriate amount of attention and good cheer toward my students that day. I was scowling maybe and preoccupied as the students filed in, and they just ignored that part or didn't see it and beamed good cheer, attention, and humor out from themselves like we'd all tried to do to the best of our abilities on previous days. Had I banked some cheer for myself just by trying to be a decent person to my students on those other days? However it happened, they were giving it back to me and didn't even know they were doing it. They were just being decent people. We'd made a space for each other to do that, be decent people even on empty days. That kind of thing-- small acts of kindness and attention-- bounce around like light bounced off a small mirror this one kid used to flash light in another kid's eyes until I told him to put it away. Even not being heavy about the mirror continues to bounce around. This theory of good humor and bouncing energy is important but must be held lightly, the way the boy held the mirror and the way he put it away again.