So when I was a kid, I had one of those orange plastic sleds that you can just lie back on and go zooming down a good hill on. Kind of like a poor man's luge. And my neighborhood had some really good hills, even just in our front yards. We rarely got snow, being in the Southeast US, but one year we wound up getting like a foot of snow, which melted a bit, then refroze, then another six inches of snow followed by freezing temps for a week.
End result was close to three weeks out of school, and conditions wherein you had several inches of packed snow, covered by a hard-as-a-rock layer of ice about an inch thick, covered by another few inches of packed snow. Sledding Nirvana. You didn't even need a sled. If you fell down, and there was a slope, you would slide. We took what snow we could that wasn't rock-hard and used it build ramps, tracks, etc.
Two moments of awesome came out of that winter.
One: Sledding down a friend's rather large yard, towards the woods. The yard was shaped a bit like a bowl, so I picked up a ton of speed going down, and figured I'd just slow down going up the other side. As I started whizzing up the upslope (in towards the trees), I noticed a slight ridge under the snow, like something buried. And remembered to my horror that there were large landscaping timbers there, marking off the wooded area from the yard. A split second later the sled hit one and stopped dead. Being that the sled was luge-like and had no handles (and was arcing up at the time), I launched cleanly off the sled like I was fired out a cannon.
I screamed and flailed as I went airborne, fully expecting to either hit a tree or fly 50+ feet and break something when I landed. After several seconds I realized I wasn't flying anymore, and hadn't hit the ground either. I opened my eyes to find the world upside-down. Literally. I started to move my legs before my brain put two and two together, and WHUMP...dropped about 10 feet into a snowbank. Apparently, in my mid-air flailing, I had managed to wrap my legs around a passing tree branch and had been hanging upside down. Oh, if only someone had had a videocamera....I'd be rich.