Once upon a time, there was a carpenter who was skilled and well-respected, deeply loved by everyone.
But the carpenter was quite peculiar; he wouldn't paint the furniture he made, leaving that work for the specialized painters.
When he made a front door for someone, he wouldn't install the door nails, leaving that task for the apprentice who specifically installed door nails.
One time, when he was helping someone make a cabinet, the person asked him why he didn't help install the door handle, which would be an easy task for him.
He replied: This is a family tradition; one should not do everything completely. One must leave some work for others.