@Patton250maybe you should hear this, it might help you understand the argument from @LanghamPor others.
You really seems to be a nice guy but with such strong ideas you don't even want to consider them as partially wrong or relative. I can't stand people who just repeat what they were told without even considering it partially biased or interested. It's a clear lack of critical mind leading to cult, religion or false believe.
I encountered that kind of mindset so much in religion or cult believing as a Mentalist who uses tricks to make people believe in extraordinary capacity that I know for a fact they're just tricks. I don't say that it doesn't exist, but I can show you a non-magical way of reproduce almost every experience people claims to have witness. So those experiences are not proofs of what they trying to make people believe.
In the case of helmet, it's kind of the same situation. You have been told since you were young that helmets saves lives, and it's irresponsible to not wearing them. But it's not entirely true, whole countries strongly disagree with that, but your ethnocentrism blind you to see that. Your mind is trying to bound those cognitive dissonances by rejecting argument, ignoring them and focusing on exemples you feel strong and not yet debunk. But you clearly defend a position rather than aknowledge the facts and conclude on you own opinion. You serving a system that told you what to think rather how to think, and this is a very concerning kind of behavior.
Considering that, I would add my own experience about protective gear. I start with nothing for 3years on a NB1E+, never fell except for one car hitting me on a crossroad (he was passing red traffic light for him). But since I tried to get my GF into euc and bought a Gotway Tesla, I wear some gears. The main reason is the speed and environment I'm in now. I ride slightly faster than before (15-20km/h before and now up to 30km/h) and more importantly I'm commonly more surrounded by cars than before where I was only using bicycle lane and pavement. But I actually measure the risk from the distance I'm going too, if I go to the shop near my apartment, I only put my kevlar jacket with built-in protection and a jeans of the same kind. But no helmet. If I have to go far away and riding around cars, I would put a helmet. But it's not because I'm affraid of my euc or insignificant low risk of mechanical failure (as long as you respect the mechanics) it's because I'm affraid of cars putting me in bad situation where I can't fall correctly.
So I'm not a guy who tell you not wearing a helmet is a good idea or not, I'm just telling you that what ever you do, please think about it on your own. And if you don't have enough knowledge, just search and confront differents opinions, ideas, studies and research from different part of the world and try to make sense of it on your own understanding. You'll may have the same position as before but at least you would received others arguments for what they are and not trying to throw them away and argue that they're wrong and irresponsible to don't have the same opinion as yours.
Ps : pardon my English, it's not my first language. Feel free to correct me or ask more precisions on sentences I might have poorly written.