Just about every time one of us leaves the house, our 14-month-old cries. Naturally, the remaining parent (or babysitter) assures him, "Oh it's okay! Mommy will come back!"
It occurred to me the other day that this is rather insulting to our son's powers of induction. Maybe he knows Mommy or Daddy is coming back, but he's still mad about the absence in the meantime. Imagine if I started whipping you and said, "Stop whining! I'll eventually stop!"