Catherynne M. Valente said this quote

“ This tub is for washing your courage...When you are born your courage is new and clean. You are brave enough for anything: crawling off of staircases, saying your first words without fearing that someone will think you are foolish, putting strange things in your mouth. But as you get older, your courage attracts gunk and crusty things and dirt and fear and knowing how bad things can get and what pain feels like. By the time you're half-grown, your courage barely moves at all, it's so grunged up with living. So every once in awhile, you have to scrub it up and get the works going or else you'll never be brave again. Unfortunately, there are not many facilities in your world that provide the kind of services we do. So most people go around with grimy machinery, when all it would take is a bit of a spit and polish to make them paladins once more, bold knights and true....This tub is for washing your wishes...For the wishes of one's old life wither and shrivel like old leaves if they are not replaced with new wishes when the world changes. And the world always changes. Wishes get slimy, and their colors fade, and soon they are just mud, like all the rest of the mud, and not wishes at all, but regrets. The trouble is, not everyone can tell when they ought to launder their wishes. Even when one finds oneself in Fairyland and not at home at all, it is not always so easy to catch the world in its changing and change with it....Lastly, we must wash your luck. When souls queue up to be born, they all leap up at just the last moment, touching the lintel of the world for luck. Some jump high and can seize a great measure of luck; some jump only a bit and snatch a few loose strands. Everyone manages to catch some. If one did not have at least a little luck, one would never survive childhood. But luck can be spent, like money, and lost, like a memory; and wasted, like a life. If you know how to look, you can examine the kneecaps of a human and tell how much luck they have left. No bath can replenish luck that has been spent on avoiding an early death by automobile accident or winning too many raffles in a row. No bath can restore luck lost through absentmindedness and overconfidence. But luck withered by conservative, tired, riskless living can be pumped up again--after all, it is only a bit thirsty for something to do. ”