"DADDY, WHY DO YOU HAVE CORN in your pants?" My three-year-old son was poking the improvised ice pack on my right hip, which partially covered a purple-and-blue bruise the size of a small pizza. After two straight days of skateboarding for six hours a day, I felt like I'd been mugged by a kung-fu gang.

Sure, it hurt. But for the first time since 1985—when a high-speed wipeout scared me away—I was skateboarding. And my teacher, eight-time World Cup champion Andy Macdonald, was confident that tomorrow I would achieve my goal: learning, at age 34, how to drop down the vertical face of a ramp, the boarding equivalent of hucking onto a black-diamond ski run.

I wasn't alone in my quest. According to a 2006 study by industry watcher Board-Trac, two million of this country's 11.9 million skaters are over the age of 18, including 205,000 between 45 and 54. Even Tony Hawk's turning 40 this year. And Macdonald, 34, further eased my apprehensions. He has an easy manner and dry wit polished through the free pointers he gives kids at his local park and the 18 years he's spent as an instructor with the famed Woodward skate camps. Woodward had put me in touch with him to set up my three-day course.

We started at an empty outdoor skate park in Poway, California. First lesson: crash technique—drop and let your knee pads take the blow. We then rode around the bottom of a concrete bowl, with Macdonald holding me. The carnage began when we added speed and difficulty.

"It's not a trick until you do it three times in a row," Macdonald said of the steep drops he made me repeat. "The first is luck, and the second is coincidence. But three times and it's a trick."

The only thing I did more than twice in a row was fall. Hard.

On day two, Macdonald took me to a three-foot-high quarterpipe. He held my wrists as I balanced the board on the edge. "Slam it down and keep your knees bent," he counseled. I crouched, stamped hard with my front foot, and rolled down the wall. No way! We walked through three more, then it was my turn to go solo, which went: Wipeout to hip, wipeout to hip, wipeout to hip, successful drop in. I tried again. The board shot out, and my head smacked the concrete.

"You OK, man?" a kid asked. I nodded, trying hard not to puke.

On day three, I met Macdonald at his home park in Clairemont, 53,000 square feet of concrete and wood operated by the YMCA. Macdonald had talked them into opening early, just for us. We warmed up for 45 minutes, then skated to a five-foot quarterpipe. I took a deep breath, leaned forward, and nailed my first try. Hell, yeah! I climbed up for another and crumpled face-first.

"Three times and it's a trick, right?" I asked, leaning on my board to stand.

"Yep." I climbed back up, ignored my throbbing hip, and dropped in cleanly. Then I did it again. Macdonald joined me on the ramp and nodded. I stared hard at the front of my board, stamped on the nose, rolled smoothly down the ramp, and headed home to a freezer full of frozen vegetables.

Woodward has schools in Pennsylvania, Wisconsin, and California. One week from $925; campwoodward.com