On the first day, God created man and said, “Eat, sleep, play, marry and enjoy your life. For this, I’ll give you 20 years.”

Happily man went away.

On the second day, God created cow and said, “You must go into the field for man all day long and suffer under the sun, have calves and give milk to support man’s family. For this, I will give you a life span of 60 years.”

Cow said, “That’s kind of a tough life you want me to live for 60 years. How about 20 and I’ll give back the other 40?”

And God agreed.

On the third day, God created monkey and said, “Entertain people, do tricks, and make them laugh. For this, I’ll give you a 20-year life span.”

Monkey said, “Monkey tricks for 20 years? That’s a pretty long time to perform. How about I give you back some like the cow did?”

So God agreed and took back 10.

On the fourth day, God created dog and said, “Sit all day by the door of your house and bark at anyone who comes in or walks by. For this, I will give you a life span of 20 years.”

Dog said, “That’s a long time to be barking. How about only 10 years and I’ll give you back 10 like the others?”

And God agreed again.

On hearing what had happened man came to God and said “I have only got 20 years to live. Could you possibly give me my 20, the 40 cow gave back, the 10 monkey gave back, and the 10 dog gave back; that makes 80, okay?”

“Okay,” said God, “You asked for it.”

So that is why the first 20 years we eat, sleep, play and enjoy ourselves.
For the next 40 years we slave in the sun to support our family.
For the next 10 years we do monkey tricks to entertain the grandchildren.
And for the last 10 years we sit on the front porch and bark at everyone.