One of the disciples of Buddha and a great Master of Zen, was asked what was it that calmness radiated out of him and he was always full of joy.
Replied he:” I eat rice when I am hungry and I sleep when I feel sleepy ! ”
“We all do that as well”, his student said.
“No, No.. when you eat , you think of this and that; and when you sleep you think of this and that.”
“When I sleep, I sleep and when I eat I only eat ” , the Master said.