I grew up with boats so I can't say when I started paddling.  Early teens, I suppose.  I recall a canoe trip on the Whitewater River in SE Indiana (no whitewater on that trip, thank god).  Four people, two aluminum tanks, and lots of turns. I followed Yogi Berra's advice that "you can learn a lot just by watching."  It wasn't pretty but we tracked well and didn't get slammed into the banks.  That was in 1972, a year out of college.

In later years I paddled when I could, doing a lot of trips on local lakes and the Kickapoo River in western Wisconsin with my ex and eventually our kids.  I borrowed and rented boats and continued to learn, slowly, by watching.

Then in 1993 I borrowed a friend's Blackhawk Nighthawk, 13'4" of twitchiness, a dump just waiting to happen.  For two days on the winding Kickapoo River I learned how to paddle a solo canoe without dumping.

In 2000 I finally bought my first canoe, a solo/tandem model, and soon afterwards got a copy of the book, "Paddle Your Own Canoe" by Gary and Joanie McGuffin.  I studied that book - and a few others - backwards and forwards and learned a lot.  I probably unlearned more bad habits than I learned good ones.  I got a Royalex tandem and started doing Class I and II whitewater.  I've had about a dozen boats since then, but I have only five left, two tandems and three solos.

In 2012 I got certified as an American Canoe Assn. moving water canoeing instructor and taught for three years until an autoimmune problem sidelined me, hopefully only temporarily.

My first BW trip was in 2009 with my son.  The learning process was similar: read up on it, listen to people who've been there before, and learn from mistakes. 15 trips later I'm not about to quit.

So I guess the short of it all is that I taught myself through experience, books, and a few friends who were only too happy to help me along.