On a hot, sunny morning, a roshi and his friend sat on the edge of a park. They watched people on the street in front of the park walking from place to place in town.
"Oh, that woman!" said the roshi's friend. He pointed to a young mother with her child. "Had things worked out differently, I might have married her. What would it have been like, I wonder? Would we have a son?"
"Your longings for things that never can happen are worse than your material longings," said the roshi. "You might as well ask yourself what might have been if you'd studied Zen as a child instead of taking it up so late in life."
"What a wonderful thought! What could I have achieved? Would I now be enlightened?"
The roshi sat frowning for a while.
"If you were the teacher among us," he said. "What would you tell me to do? What would you tell yourself?"
His friend closed his eyes in thought. When he opened them, he pointed to a nearby tree.
"Let's go sit in the shade," he said.