With my grandson, the traditional game of peek-a-boo became exciting fun when he realized my face would reappear, along with an enthusiastic "boo". He began realizing I hadn't actually ceased to exist because I hid my face. And when a toy is hidden or he drops something, he knows to look for it. These stages of development are a joy to watch. I believe this concept of permanence plays a role in our spiritual and emotional lives, too, because sometimes we fool ourselves into thinking that things we hide about ourselves don't exist.