Fall

After I cut all the leaves in the yard to shreds with the mower, I went inside for a drink of water. When I came back out, I saw that new leaves had fallen. They were yellow leaves, which confused me. I looked up in the trees and most of the leaves still on the branches were green. And the leaves previously on the ground, since mulched by the mower, were brown. Whence then did the yellow leaves come? I pondered and thought perhaps the green leaves turn yellow before they fall off. And then they turn brown as they lie on the ground dying.