I'll never forget the first time my son had a taste of real food. I mean something other than Mom's milk or formula. It was a little bite of honeydew melon. The look on his face was priceless. A whole new world of possibilities had opened up to him. Kids just seem to be more in touch with our primitive nature than are we adults. It's largely because, at a young age, they haven't been taught those things that separate us, in modern society, from our primitive legacy.
Kids will enjoy an apple or a banana, up to the point that you give them a big piece of chocolate cake. Somehow the easy sugar intake can easily become nearly addictive. We need to learn lessons from them by observing how they naturally act and react to the world around them. Watching their actions is such a valuable resource, that it's a shame to waste.
Watching kids on a playground, if unsupervised, is like turning the clock back a few thousand years. They run, they wrestle, they climb, they get on the ground, they get up, they fight over possessions. In order to prepare them to live in "polite society", we have to teach them some boundries, of course. It is just my hope that, in the process, we don't stifle all of their naturally wonderful abilities. We teach them not to run with sharp things in their hands instead of HOW to run with sharp things in their hands. I'm not telling you to have your kids run with the scissors, but at some point, they have to know how to carry sharp things, how to cut things with a knife, etc. The age at which an individual child is ready will vary, of course.
Kids will find a way to have fun with anything. It doesn't require a PS-3, or other sophisticated gaming device. Give some kids a pile of dirt and they will invariably end up playing "king of the mountain". Give them a bunch of tree branches laying in the yard after a pruning session, and they will be fencing with them, or using them to knock leaves off of high branches. That's what they do, because that's what they were evolved to do. Don't make the mistake of parking them in front of the TV with a plate full of cookies or a bowl of sugary cereal. Give them the means to move, give them good REAL food, and watch them go. You might just learn something!