It seems that when God was making the world, He called Man over & bestowed upon him 20 years of normal sex life. Man was horrified! Only 20 years of normal sex life? but the Lord was adament that that was all man could have.

Then the Lord called the monkey & gave him 20 years. But I dont need 20 years, he protested. Ten is plenty for me. Man spoke up eagerly, Can I have the other ten? The monkey graciously agreed.

Then the Lord called the lion & gave him 20 years. And the lion, like the monkey, wanted only ten. Again Man spoke up, Can I have the other ten? And the lion graciously agreed.

Then came the donkey & he was given 20 years, but like the other animals before him, he felt that ten years was sufficient. And once again Man asked for and received the remaining 10.

Which explains why man has 20 years of normal sex life-
10 years of monkeying around –
10 years of lion about it –
AND
10 years of making an ass of himself.