Old Man and the Rocking Chair

A man came walking up to his grandparent's house when
he noticed his grandfather sitting on the porch, in
a rocking chair, with nothing on from the waist down.

"Grandpa, what are you doing?" he exclaimed. The old
man looked off in the distance without answering.

"Grandpa, what are you doing sitting out here with nothing
on below the waist?" he asked again.

The old man slowly looked at him and said, "Well, last
week I sat out here with no shirt on, and I got a stiff
neck. This is your grandma's idea."