I know I have possibly over-romantic ideas of things like this - probably enhanced by years of reading books, anything from The Boxcar Children to Secret Garden. I delight so much in my kids having parent-free time to build a world of their own. Not because I want them gone, or quiet, but because I feel that autonomy is so important for them learning for themselves early on who they really are.
For a couple of years now the kids have been spending lots of time with neighbor kids and by themselves playing in "The Cherry Tree Forest." Even though it's right across the street, I've never been there. My knowledge of what they do there has been limited to the stories they tell me, eyes wide with excitement, over their dinners.
But the forest became irresistible to me when they put up their "No Trespassing" sign. I wanted to see what else they had created with their imaginations and the treasures they found on this old unused lot. So I asked them to give me a tour, and with such pride they ran from one "room" to another, showing me their inventions and creations, telling me who got hurt tripping here, and who rigged that tent, or discovered that sand box.
I'm guessing that some day, years and years from now, they'll look at these few pictures, and layers of accumulated but somewhat hazy memories will come flooding back to them. Moments that, though often forgotten, have contributed substance to the fabric of their selves.