Usefulness is not the same as worth

A carpenter and his apprentice were walking together through a large forest.  And when they came across a tall, huge, gnarled, old, beautiful oak tree, the carpenter asked his apprentice: "Do you know why this tree is so tall, so huge, so gnarled, so old and beautiful?"  The apprentice looked at his master and said:

"No... why?"

"Well," the carpenter said, "because it is useless.  If it had been useful it would have been cut long ago and made into tables and chairs, but because it is useless it could grow tall and so beautiful that you can sit in its shade and relax."

Tao story.

"In solitude we become aware that our worth is not the same as our usefulness... In solitude we can grow old freely without being preoccupied with our usefulness and we can offer a service which we had not planned on."

Henri Nouwen (Out of Solitude: Three Meditations on the Christian Life)

I don't particularly want to be someone who is remembered for being good at things or for achievements.
I would like to be a person in whose shade others can sit and relax.