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 remember to catch the world in it's changing and change with it.