Sam McNerny of Big Think used a recent article to ask why kids draw pictures of monsters but adults don't. It's that kind of creativity that dies out over time, either due to natural causes or slow execution from the education system.
In many ways, children flourish where adults fail. Children are more creative and are natural inventors. Their worldview is incomplete and demands discovery. They prosper because they embrace their ignorance instead of ignoring it. And they are willing to explore, investigate and put their ideas to the test because they are willing to fail. Unlike adults, they don't care how other people perceive or evaluate their ideas, and they're unconcerned with the impossible or what doesn't work.
The article echoes sentiments that many people have espoused throughout the years. Ken Robinson notably speaks on the subject in some fantastic TED Talks (which I highly recommend) and he is also mentinoed in the article, saying that the school system as it is now is essentially solely designed to lead in to college. Of course, I'd love to see schools encourage flights of fancy rather than reining kids in to the expected—there are countless stories of kids thought to be ADD who just needed something to focus on—but I also think there's something in here that applies to games specifically. The essay mentions that besides the educational system, one reason our creativity and curiosity fades is a physical one:
[R]egions of the frontal cortex -- a part of the brain responsible for rule-based behavior -- are not fully developed until our teenage years. This means that when we are young our thoughts are free-flowing and without inhibitions.
On the playground, there were no rules unless we made them. We played without pieces or turns, just running and shouting, throwing and dodging imaginary fireballs, bullets or magic spells. Games are basically rule-based systems. They're great for allowing the player to explore, discover and learn within them, but they only offer a very specific kind of play. The world is built on rules and when we play games, we swap one set of rules out for the other. Kids take very few tools—playground or rubber balls or maybe just open space—and create entire worlds out of them, worlds without rules or boundaries that are constantly shifting, being redefined by everyone around them.
There's a lot we can learn from children and a lot of it that could change our games. One of the best things about games is their potential for emergent gameplay, the ability for people to discover new ways to play the game that weren't intentional. These bits of gameplay are a new type of play, unanticipated by the designer, yet beautifully creative. I love games that allow for emergent gameplay and creativity (which is a big reason I love Starcraft) but I'd also really like to see games that forgo the idea of set rules and instead just go crazy with letting players define, redefine, shape, morph and break them. I don't want to play your game, I want to play within your game.