There was a mechanic at the JD dealership 50 some years ago.
He had a shortened finger.
His brother shortened it for him.
When they were younger and were chopping wood,
He laid his hand on a chunk of wood and dared his brother to swing the ax,
He thought that his brother would not do it or at least not hit that spot,
His brother thought that he would move his hand.
At least this is how he explained the curled up finger nail.