45 years ago I was a mechanic at the local motorcycle shop. After repairs, we used to take the dirt bikes for a short spin on a trail through the woods. This trail skirted the top edge of a 100ft tall gravel pit cliff. Unbeknownst to us, they had recently removed some dirt and the trail was no longer there. One of the mechanics went roaring up the trail and into space. Tumbled all the way down to the floor of the gravel pit. Got beat up pretty badly. Ever since, I try to make sure I know what's ahead, or go slow enough I can negotiate it.