I'll miss you Grandpa

The dead are always looking down on us, they say.
while we are putting on our shoes or making a sandwich,
they are looking down through the glass bottom boats of heaven
as they row themselves slowly through eternity.

They watch the tops of our heads moving below on earth,
and when we lie down in a field or on a couch,
drugged perhaps by the hum of a long afternoon,
they think we are looking back at them,
which makes them lift their oars and fall silent
and wait, like parents, for us to close our eyes

Billy Collins.