I spent the better part of my youth doing Oddessey of the Mind (which has gone through some difficulties and splintered as near as I can tell), programming, bicycling, and playing D&D.
D&D was both entertaining and also wildly educational. I was in a bunch of campaigns and we were studying architecture, history, military campaigns, meteorology, the middle ages, math, economics, sociology, philosophy and a variety of other topics to create worlds that were fresh, inventive and believable. As such, I, too, salute Gary Gygax on his way to the other planes.
As a side note, I noticed a large overlap between programmers around my age and D&D players.