Arnold Bennett said this quote
“ Ardour in well-doing is a misleading and a treacherous thing. It cries out loudly for employment; you can't satisfy it at first; it wants more and more; it is eager to move mountains and divert the course of rivers. It isn't content till it perspires. And then, too often, when it feels the perspiration on its brow, it wearies all of a sudden and dies, without even putting itself to the trouble of saying, I've had enough of this. ”