I was chatting with a friend not long ago when he mentioned a comment made to him by a retired commandant in the U.S. Marine Corps: “Your relevance once retired is a nanosecond.” Happily, that’s not true in many industries—not if you write articles and thought leadership pieces for trade publications and amplify their impact via social media. As a “retired” financial services executive, I’ve had scores of articles published online and in print at publications like this one in the U.S., Canada, and the U.K. As with most successful endeavors, the first step is getting a foot in the…