That's a good question. Speaking from experience: I am a programmer like my father, but my older brother is not. My dad and I discuss programming all the time,

That's a good question. Speaking from experience: I am a programmer like my father, but my older brother is not. My dad and I discuss programming all the time, but he doesn't take much interest in my brother's hobbies. For what it's worth, he tried to steer me towards programming from a young age, but it never really stuck; we never built anything interesting. I did, however, write some simple games for my TI-83+ calculator, and finally I rediscovered serious programming in college. My guess is that Ryan is primarily interested in programming as a means of making games. And since his father basically wrote the book on that topic, he's in a perfect position to nurture that interest. If John instead wrote, say, the world's best accounting software, I think Ryan would be more likely to pursue a different hobby.