That’s the problem with “success.” After so many years of climbing your mountain, it’s not until you reach the top that you realize the next step is down. And the next mountains after that are lower. What could DHH do that would surpass the thrill of creating Rails or hitting the New York Times best-seller list?
Who's to say that a focus on "success" is what got Heinemeier Hansson to the top of this particular mountain? One way to be effortlessly successful is to just do what you love and thus do it really well; that and a lot of luck can in fact get you a race car.
This perspective that life is a narrative with upswings and downswings can itself be treacherous. Your life is not a prewritten narrative with defined story arcs. You should try to make sure you're happy with what you're doing now, and o do what you can to mitigate future risks and pay down your retirement. But I'm not sure there's much to be gained from explicitly plotting your ultimate success.