“That’s very kind of you,” I said, “but why are you doing this for a stranger?”
“Well, yesterday I woke up with a toothache and I took it out on everyone in sight. This morning I feel fine. So today I’m making up for yesterday: favors for the customers, kind words for the help. That’s how I pay off for the bad days.”
As I drove off, I thought, “Now there’s a man who makes sense: he settles his personal accounts day by day.”
That is what learned people call “mental hygiene.” The tiny patch which the filling station attendant put on my tire saved me only a dollar. But it saved him a week’s worry about yesterday’s meanness.