They streak overhead on cloudless days, crisscrossing the clear blue sky with white fluffy brushstrokes that trace our incessant rush to be somewhere else.
From ground level, I watch jetliners etching their way from New York to Miami, 32,000 feet above Charleston, as they cruise up and down the eastern seaboard.
Sometimes, to the casual observer, they appear to be on a crash course and will surely hit head-on when the condensation trails collide.
But they don't. They are thousands of feet apart in elevation, guided by computers that hum quietly in non-descript buildings far away.
At any given time, there are thousands of planes in the air around the world. And even if the air traffic controllers are asleep in their towers, the sky is a big place.
For more than 20 years I was one of those passengers, scrunched into the middle seat on row 36 near the bathroom at the back of the plane.
To travel for a living can be a living hell. Just ask those who do it. Out on Monday. Back on Friday. Every week. Every year. For a lifetime.
You can easily spot them. They're pros.
They park in the same spot in the long-term parking lot every week. They know the shuttle bus schedules. They breeze through security. They have personal relationships with the gate personnel.
They have everything they need neatly packed in a carry-on bag, or two. They check nothing.
They rent the same cars. They stay in the same hotels.
They are usually reading a book or working on a laptop or iPhone. They seldom make eye contact. They have more frequent flier points than they will ever use, but they keep close track of them because it's how they keep score.
They are road warriors.
Once you deplane, get off the road and return to real life, you see air travel for what it really is -- a necessary evil.
Long gone are the days when flying was a luxury, a special occasion, something to look forward to. In today's world, the friendly skies are filled with disgruntled passengers stuffing oversized bags into overhead compartments whether they fit or not.
It's sitting next to somebody for four hours who either snores, is overweight, hasn't bathed, is afraid of flying, talks too much, is holding a screaming baby or brought their own liverwurst lunch.
It's running through airports trying to make impossible connections, getting stuck behind a family of five en route to Disney World, listening to a group of football fans sing their fight song 50 times, sleeping in a plastic chair because your flight was cancelled, eating too much airport food or trying to survive on a pack of peanuts.
That's why I enjoy sitting back on a nice clear day and watching those jetliners passing overhead, and being thankful that I'm not on one of them.