We are so little reconciled to time that we are even astonished at it.  “How he’s grown!” we exclaim, “How time flies!” as though the universal form of our experience were again and again a novelty.  It is as strange as if a fish were repeatedly surprised at the wetness of water.  And that would be strange indeed; unless of course the fish were destined to become, one day, a land animal.

– C.S. Lewis