Isaac Newton hears his parents screaming at each other one afternoon

Mrs. Newton: "I've had enough of this. I want a divorce!"

Mr. Newton: "But why?"

Mrs. Newton: "Do you think I don't know about the other women? How stupid are you? I can see the tramp's lipstick on your cheek."

Mr. Newton touches his cheek, a perplexed look on his face. Isaac, saddened by their fighting, runs out the door.

He's soon sitting in an orchard, taking shelter beneath an apple tree. He thinks he's finally found peace when an apple falls from the tree and smacks him on the head. The pain is intolerable, and he runs home crying.

"Mother, mother! I was sitting beneath an apple tree, when an apple fell on my head and hurt me. Why did that happen?"

Mrs. Newton sighs and says, "The apple doesn't fall far from the tree."