When I was little, my empathy was boundless and always on, attuned to any living thing in the area. I cried over sick, winged things, sighed and sat quietly with cats, and begged my mother to punish me instead of the sisters who were in trouble for something they had done to me. (They would often join in, "Yeah, spank her!" *see my wry smile here*)
But then someone reaches in past the boundaries you've carefully placed by simply being really sad and in the same space you happen to be in. You say the right words, you make yourself small and quiet, and you hope they don't see you shaking. You shake because when the empathy is on and going full blast, you see how fragile everyone is, they are all brittle bones and weak hearts and shuddering breaths, and you've got to be so careful, so awfully, terribly careful with the wounds they've often unknowingly bared.
And for a few days after an episode like that, I still feel careful with everyone I meet, down to the mere flashing of eyes when I pass them in a hall, because I've been reminded that everyone feels; that there is a world of secret going on behind their crossed arms, and they may need my careful hands and quiet heart today.
And it's exhausting to be so careful, so aware. I sleep the best after the days that I care.