I hear it approaching and my hand reaches to my side, where I don’t keep my holster. The noise of tires running over the tarred surface intensifies, and at any moment the vehicle will crest the hill. My fingers, next to the pistol handle that isn’t there, itch and tingle. Then comes the flash of the sun bouncing off the roof of the pickup truck and, in a whoosh, the entire truck comes into view and I see a middle-aged man at the wheel.

Before he can make a move, I lift my hand in the air, extend my palm wide, and wave hi. My hand goes up. I count to two. My hand goes down. My aim is true and the driver waves back at me before he zooms past.

People say hi back to me in all sorts of ways. Many use my preferred “up-two-down” method. Another option is “the wheel,” a popular choice for those who drive with only one hand on the steering wheel. They wave by keeping their thumb curled around the wheel and lifting up the other four fingers.

The “windshield wiper” is a method I rarely encounter. It is analogous to seeing in your backyard a bird that typically lives year-round on another continent. It involves raising the hand, extending the palm, and moving the hand to the right, to the left, to the right, and to the left again before coming down to the rest position. As you can see, it’s pretty complicated and not for the faint of heart.

Some drivers wave back with a nod of the head. I prefer receiving a wave of the hand rather than a nod of the head because the nod’s intent is unclear. Hi, I say. Yes, they say.

I must admit, when my Lab, Echo, and I first took to walking on Cundy’s Harbor Road many years ago, I wasn’t much of a waver. I would wave back only when someone in a car waved at me. But now I do it all the time and take pleasure in always trying to be the first one to say hi as a car approaches. I’ve discovered that waving to people on the road is energizing. For a swift second I make a connection with someone else who is also on the road of life — and Cundy’s Harbor Road. I don’t know what people are thinking when they wave at me, but when I wave at them I hope they translate my simple gesture into the following message: Hi! I see you! I wish you a safe journey.

There are other places where it’s socially acceptable to say hi to people as they pass by. Boat rides and hikes come to mind. What is odd, though, is that what is socially acceptable in one context becomes socially unacceptable in another and might lead to a review of store surveillance footage. I can say hi to a hiker on a trail, but I know I shouldn’t say hi to the same hiker in a grocery store as we push our carts past each other. I also understand I can’t go around saying hi to everyone in the waiting area at a car repair shop. Why is it not OK to say hi to people wherever I find them?

This is just one of the impenetrable mysteries of life I wonder about.

Dear reader, as our time together comes to an end, know I am employing the windshield wiper method and waving at you. I hope you will wave back.

I see you! Safe journeys.

Gregory Greenleaf lives in Harpswell and teaches high school English. He ascribes, prescribes and subscribes to many old-fashioned ideas, but especially Charles Dickens’ observation that “There is nothing in the world so irresistibly contagious as laughter and good humor.”