I play the game again now, as a 47-year-old, mostly grown-up person. Today, with my +5 Goggles of Hindsight, I can see how D&D was subtly helping me come of age. Yes, it’s a fantasy game, and the whole enterprise is remarkably analog, powered by face-to-face banter, storytelling and copious Twizzlers and Doritos. But like any pursuit taken with seriousness (and the right dose of humor), Dungeons & Dragons is more than a mere game. Lessons can be applied to the human experience. In fact, all I really need to know about life I learned by playing D&D.
Don't regret for a second the years playing D&D. Then AD&D. Followed quickly by Paranoia, Rolemaster, GURPS, various MUDs, EQ and beyond. In hindsight, and contrary to some of my peers' and parent's beliefs, they've all been incredibly positive and worthwhile experiences that helped me prepare for real-world challenges and more importantly meet and keep a ton of real-world friends.
My favorite cartoon from Dragon magazine carried me well into the workplace. It basically had a guy sitting at his bosses desk saying "I've been to the 9 planes of hell, been damned by demons and tortured by demi-gods and you really think I'm scared because you threaten to fire me?"