"Why'd you do that?" his apprentice Henryk asked, finding it silly.
"The trees don't like surprises," he replied, winking.
Years passed. The merchant died. On Henryk's first journey alone, he didn't greet the trees.
It turned dark. The woods crowded the road. A root rose up and tripped him. He ran the rest of the way.
Next year, Henryk greeted the trees. "Hello! Just passing through! Apologies for the intrusion!"
"Why'd you do that?" his apprentice asked.
"Trust me. They really don't like surprises."