excerpted from cracked.com's '5 gaping plotholes hollywood know you won't notice'
January 10, 2010
...We're calling it Peekaboo Ending because it relies on the same ass-backwards logic that makes infants squeal with delight when someone hides and unhides their face. When we're born, we believe that things stop existing if we can't see them. To an infant's mushy, half formed brain, peekaboo looks like their mom is blinking in and out of existence with a stupid look on her face. Roughly translated, those squeals mean, "Holy shit, moms a wizard."