I guess what most of us forget from time to time is that when we are "out there" - be it a county park, an ocean beach, a quiet lake - we are on someone else's turf, and Mother Nature can try very damned hard to kill you if you do not give her the respect she demands.
One of the most powerful examples of the truth of that statement that I have ever seen was at Grand Canyon National Park, in one of the most heavily-travelled areas. It was a photo of a pair of glasses, a lens chipped, an ear piece bent. That was all they ever found of the tourist who went for a short off-trail hike, in what is admittedly one of the most over-developed national parks in the U.S. He just vanished ...