Ralph Helfer said this quote

Trees are like people and give the answers to the way of Man. They grow from the top down. Children, like treetops, have flexibility of youth, and sway more than larger adults at the bottom. They are more vulnerable to the elements, and are put to the test of survival by life's strong winds, rain, freezing cold, and hot sun. Constantly challenged. As they mature, they journey down the tree, strengthening the family unit until one day they have become big hefty branches. In the stillness below, having weathered the seasons, they now relax in their old age, no longer subject to the stress from above. It's always warmer and more enclosed at the base of the tree. The members remain protected and strong as they bear the weight and give support to the entire tree. They have the endurance.