For the past couple of days, my younger son and I have been trying to cure our nature-deficit disorder. Right now, I’m sitting in bed in a Bishop, California motel that, well, isn’t the Ritz. Matthew, who is 23, is still asleep, and deeply. A few hours ago we staggered across the clumped grass and mud along the Owens River, struggled to keep our balance as 40 mph gusts tangled our…