Thats easy to say but the fact is we all take chances, do things we know are risky even dangerous. Often the difference between getting away with it and spilling some blood is experience and/or your state of mind, if your tired or in a hurry, etc., etc. An experienced person is aware of the possible consequences of what he is doing and avoids the pinch points. A non-experienced person often doesn't realize, "that action is a no no", until the blood flows. HOWEVER, like life, no one can be 100% aware of the dangers, 100% of the time. Guard where you can.
While completing the heating duct work on a house I built in 90-91 in the Ottawa area, I sliced the back of my hand open. I was tired, it was getting late, and the light was dim. I should have stopped earlier but I wanted to get the job done. One slip with the snips and the back of my hand was gashed open. I put some gauze and tape on it and finished the job. The wife and doctor made a big deal of it, and I ended up with half a dozen stitches. In hind sight stopping earlier and finishing the next day would have been easier. Hind sight is always so smart, lol.