I've carried a pocketknife whenever I've had a pocket for over 30 years now. I don't want to be without basic tools, which also explains the combo screwdriver and small forceps in my eyeglass case. People merely think I'm weird if I take out my screwdriver or forceps. But they back away if I have to take out my knife. Being without tools makes me feel vulnerable.
Perhaps that's because man is really a toolmaker, and not a predator. High-definition color binocular vision is intended for making tools, not for being a predator, like a hawk.