Where's Lily?

So I used to think that kids outgrew that whole "peek-a-boo" thing. For us, it has ceased to amuse her when we "peek-a-boo", however when she is the designated 'peeker' she really seems to enjoy it. In fact, when Lily hides her face, and we don't immediately say "Where's Lily? Have you seen her?", she starts giggling and says, "Where's me? Mommy, where's me?"