There is an inherent, humbling cruelty to learning how to run white water. In most other so-called "adrenaline" sports—skiing, surfing and rock climbing come to mind—one attains mastery, or the illusion of it, only after long apprenticeship, after enduring falls and tumbles, the fatigue of training previously unused muscles, the discipline of developing a new and initially awkward set of skills.Running white water is fundamentally different. With a little luck one is immediately able to travel long distances, often at great speeds, with only a rudimentary command of the sport's essential skills and about as much physical stamina as it takes to ride a bicycle downhill. At the beginning, at least, white-water adrenaline comes cheap.It's the river doing the work, of course, but like a teenager with a hot car, one forgets what the true power source is. Arrogance reigns. The river seems all smoke and mirrors, lots of bark (you hear it chortling away beneath you, crunching boulders), but not much bite. You think: Let's get on with it! Let's run this damn river!And then maybe the raft hits a drop in the river— say, a short, hidden waterfall. Or maybe a wave reaches up and flicks the boat on its side as easily as a horse swatting flies with its tail. Maybe you're thrown suddenly into the center of the raft, and the floor bounces back and punts you overboard. Maybe you just fall right off the side of the raft so fast you don't realize what's happening.It doesn't matter. The results are the same.The world goes dark. The river— the word hardly does justice to the churning mess enveloping you— the river tumbles you like so much laundry. It punches the air from your lungs. You're helpless. Swimming is a joke. You know for a fact that you are drowning. For the first time you understand the strength of the insouciant monster that has swallowed you.Maybe you travel a hundred feet before you surface (the current is moving that fast). And another hundred feet—just short of a truly fearsome plunge, one that will surely kill you— before you see the rescue lines. You're hauled to shore wearing a sheepish grin and a look in your eye that is equal parts confusion, respect, and raw fear.That is River Lesson Number One. Everyone suffers it. And every time you get the least bit cocky, every time you think you have finally figured out what the river is all about, you suffer it all over again.