One thing I've had my kids do every year since they could write, is create an Illustory book. They come up with a story, illustrate it, and then mail it to a company which turns it into a hard-cover book. The kids like to reread them, looking back and see how their writing and drawings have improved, and seeing what exactly was on their minds each year.
Yesterday, my nine-year-old son found one of the books he had written when he was six. He sat on the sofa and read through it. After reading it, he became rather sentimental. "Mama, this reminds me of when I was a kid."
"When you were a kid?" I asked. "Aren't you still a kid?"
"No," he replied. "When I was a kid, we lived in Cincinnati, and I had a lot of friends. It was fun back then. Now I'm grown up. Not so much fun. I wish I could go back to the good old days."
(Hate to tell you, kid, you're still in the good old days. Just you wait until you become a real grown-up!)