I must have been eight or nine years old. It was summer. I was playing in the garden at home, and I think I lost a ball of some sort in a well-stocked herbaceous border. In bending down looking for the ball, I failed to notice a narrow cane that was one of several there to support the plants. It was painted green so it blended in(!) I was so lucky that it missed my eye and merely pierced my cheek half an inch below.
I have never forgotten that, and to this day I put caps of one sort or another over the ends of canes and other similar things. In recent months it has been lengths of rebar, which I use for marking out hard landscaping. They are fairly obvious now, during the day. But at twilight, and later on in the season when the weeds are high, they are hazards. I put brightly coloured empty shotgun cartridge cases over them. ...Which also helps rid the countryside of a little trash. Or, for better visibility at a distance (when gauging the smoothness of a long curve marking the line of a new path, perhaps), I slide white electrical conduit over their whole length.