I once asked the nurses in the intensive care ward, where my baby son was, why they didn't work with adults rather than children. Surely the heartbreak was hard to cope with? They said it was because children didn't know they were supposed to be ill so they didn't lie around moaning like adults did—as soon as they felt a little better they would jump up and go and play with their toys. It was much more satisfying having patients who (if they got better) you saw go from coma to running around again full of joy.
Management of and varying response to compassion fatigue.
There's a happy period where you're doing extremely fulfilling work, then a difficult time when you're distraught at your failures, then a complete indifference to suffering that you've normalized.
Managing fatigue and stress in any job is extremely important, managing compassion fatigue is even more so.