After designing Ultima Online, Raph Koster went on to write A Theory of Fun for Game Design, a book for game designers with a lesson for all of us. After ten years, it’s being republished, and its lesson still applies. We need to learn how to have fun. 

“After we grow up, we sometimes wonder, ‘Where did the fun go?’” he told Wired in an interview posted today. Koster says that the lack of fun in the adult lifestyle has to do with grown-ups becoming overly familiar with things. We’ve mastered all the thought patterns we need to know, whereas those of kids are still developing. “Just using it isn’t necessarily fun. It’s pushing at the edges of it that’s fun,” he said. 

This is in line with studies that show that five-year-olds are more perceptive than fifty-somethings. The younger subjects notice more details in the world surrounding them, while you likely hardly notice the office buildings and shrubbery that you drive by on your way to work every day. The key to feeling young and playful is often in taking notice of the peculiarities in your day, according to an article on how to stay mentally fit, in the New Yorker. 

“With age, some games turn serious,” he writes. Maybe we just need to try some new games.