What I miss most about childhood is the mystery, the magic, not knowing that there are limits.
I miss believing that the red light from a high flying airplane is Rudolph, pulling Santa's sleigh. Or wondering what mysteries lie over the hills in the distance, thinking that if I could go over them I would discover things that no one else has. Or gazing down the length of the crawlspace beneath the house and thinking that light, far away, was an underground city.
It's a disappointment to know that the red light is an airplane. That over those hills lies yet another subdivision. The underground city is no more than sunlight coming through a small vent in the concrete.