Everyone has them. You can't predict when you'll get them, but you know them when they happen. I'm talking about those moments when you understand everything with perfect clarity.

It's that moment when you achieve total oneness with the universe, a moment so profound that it transcends the very idea of human awareness. It isn't "peace" or "nirvana" or even really good drugs. It's way beyond that.

I've had 11. The ones I can mention (without making someone else really mad) are when I held my first newborn daughter, my first jump from an aircraft and the first time something I built fired a golf ball more than half a mile.

Unfortunately, you can never recreate moments like that. They're firsts. Once you've had the experience, something in you permanently changes. Your brain says, "Been here. What else have you got?"

There are those other times, though, moments when that oneness with everything is the result of a perfect juxtaposition of place, time and intent.

In the summer of 1997, I rafted the upper Green River with a group of friends. The day was hot and windless. A few of us jumped into the river and floated along in our life vests.

The river was calm for several miles. Drifting in the warm, silent current, I watched hawks cruise overhead until I fell sound asleep in my vest.

I have no idea how long I napped in the Green, maybe a million years back in time. When I awakened, there was a brief moment when I was part of the entire world. Drifting under towering cliffs was like browsing in God's library.

Then some *%&!# threw a bucket of water on me and the moment was gone.

Granted, a sharper moment of clarity would have been to wake half a second before being sucked into a rapid or snatched under by a giant Green River razor eel. (Note: There's no such thing.)

Terror provides amazing clarity but very little solace or understanding. If you want that moment when whatever passes for your soul undergoes a transformation, you need the right place and the lull of millions of years.

It's been a long time since a river did something like that to me, since before my wife's cancer. For years I wanted to coax that feeling again, but I've always put it off.

Last week, some friends and I booked another shot at it. Five days and four nights down Desolation Canyon of the Green River and 100 million years back in time. We'll launch May 31 from Sand Wash and raft 90 miles to the town of Green River.

Five days of sleeping on sandbars while the cosmos wheel, drifting past abandoned ranches, and through the forgotten cemeteries of the ancients, should be enough to get that moment back.

Come along if you're interested. And if that life-altering moment doesn't find you, we can always fall back on terror.

Robert Kirby can be reached at rkirby@sltrib.com or www.facebook.com/notpatbagley.