The trees are holding their breath.

Waiting.

This is the last time they will be green this year.

Like the whispered hum of a crowd before a fireworks display, the trees are anxious. Soon their leaves will explode. Firey reds, velvet oranges and soothing yellows will catch the light of the autumn sunset and illuminate the horizon. As the days and nights become colder, the leaves will fall, spinning, to cover the sidewalk in a patchwork quilt of color. Below the empty trees, these leaves will lie until they are covered by the first snow and finally disappear.

"There is a last time for everything."

These words were said to a friend of mine by a wise man named Woodchuck. Though I was not there, I can imagine the moment - a cold, clear summer night, under an infinite Adirondack sky, where the edges of the Milky Way spiraled away into the blackness above their heads. They were saying goodbye, my friend and Woodchuck, and as far as they knew, they were never going to see each other again. This was their last time, together.

Last times are sad. Or at least we perceive them to be. They represent, to us, a sense of finality, of endings, of loss, of death. Things never to be done, seen or felt again - last dances, last kisses, last good-byes. We make a big deal out of last times, celebrating them with parties and ceremonies usually accompanied by tears and hugs. We feel the moment rushing past, and we are afraid to let go. A sense of emptiness finds its way into our hearts, and later we try to relive these past moments in our daydreams, or by flipping through photo albums or watching home videos.

First times, however, are perceived as happy occasions. They represent excitement, hope, energy and, most of all, innocence. Like champagne bubbles, first times tickle our nose and make us buzz. Fresh and clean, first times are not bothered with what happened before this very moment ... because this very moment has never happened before.

Why last times should be sad and first times happy is surprising. They are really one and the same - two different words used to describe the same fleeting moment. Every first time is a last time.

A first time never happens again, ever.

This is the last time you will live through this day for the first time. This is the last time you will be kissed by a new lover for the first time. The touch of unfamiliar lips, causing you to jump and stumble inside. This is the last time you will hear a song for the first time - your brain struggling to interpret new rhythms. Rhythms that will, in time, become as familiar to you as a heartbeat.

This is the last time you will notice for the first time the dimple that appears when he smiles. This is the last time you will realize for the first time that her eyes are green. This is the last time your daughter will count from one to 10 for the first time without forgetting eight.

This is the last time you will say "Hi!" to a stranger for the first time. A stranger, who later will be like a broken-in wallet that fits comfortably into your pocket. This is the last time you will try a margarita for the first time with salt. This is the last time you will lean against the Athens' bricks for the first time - eyes shut, feeling the last of the summer's warmth wrapping around you.

Last times, first times are a beating heart. Each moment, rolled in energy, is alive. Each one breathes, briefly, and then dies in an exciting flash, to be replaced by another breath. And the chain of these breaths makes life.

This is the last time you will be innocent.

Enjoy it.

"Sometimes one finds in fossil stones the imprint of a leaf, long since disintegrated, whose outlines remind us how detailed, vibrant, and alive are the things of this earth that perish"

-Diane Ackerman

Ferrell, an Environmental Studies graduate student, appreciates comments at kf899692. Par Avion appears on Fridays.