From The Aesop's Fables : The Gnat & the Bull

A gnat was flying and it landed on one of the horns of a bull. He remained sitting there for some time. When it had rested enough and was about to fly away, it said to the bull, 'Do you mind if I go now?' The bull merely raised his eyes and said, Its all the same to me; I didn't notice when you came, and i would not know when you go away.