Why is that?
For a moment I consider that it’s like when a baby loses a tooth, but then I realize, no, it’s more rare to witness any given tree dropping a leaf than a child loosing their tooth. You know how many teeth your child will loose as they mature, you will be there for many of them, and those extractions you don’t witness, you’ll be informed about, in most cases you’ll hold the tooth in your hand, you might sneak it out from under a pillow and leave a silver dollar in its place.
That leaf that you see falling from a tree is more like one of innumerable hairs falling from a head, which when you think of it that way, at first, it seems like no occasion for awe. People shed hair all the time, and so must trees shed their leaves, even when it’s unseasonable.
Why then the awe?
Because it’s an intimate moment shared with this random tree. I may never see it loose another leaf. The next time I pass, it may be a still bit of scenery, either naked, or covered in orange or green foliage. It will give an impression of being static, as if it has always stood thus. My attention will be attracted to the moving objects in the environment, humans, birds, cars, cats. If I take note of the tree, it will be of the whole tree, or the entire canopy of leaves shimmering with sunlight, but not of that moment of separation, that instant when a small part of the entirety falls.
I suppose that is where the awe originates.
To see a leaf fall is like witnessing a birth, the moment when something that was a part of one thing emerges suddenly distinct and isolated. Behold the brave leaf twirling gracefully towards the earth, a solitary thing, dancing on the wind, lost eventually to the mulch. It’s a lifetime that lapses before my eye for a duration of time that I call 3 seconds.
Likewise, I am still twirling in free fall, no longer what I was, not yet what I will be, a thing in motion, excited, confused, thrilled, frightened, streaking through a duration of time with definite limits. Transience, mortality, in the falling of a leaf. The mirror of my own existence.
Every time I catch sight of a falling leaf I have witnessed my own transgression.