It's that time of year when folks venture up ladders and out onto their roofs, putting up christmas lights and other holiday decorations. My own house is lit up such that it is probably not visible from space, but could serve as a beacon for passing aircraft. (Energy-efficient LEDs, of course.)
Anyhoo, it turns out that if you're not really accustomed to working on a ladder or walking on a roof, and if conditions are cold, wet and icy, or if the roof is mossy, the chances of suffering an acute and traumatic case of gravity are pretty decent.
Be careful out there.