I used to ride around for years without a helmet despite laws that mandate that I wear one. Interestingly, even after two tickets I still rode around without a helmet because I perceived that I was an awesome cyclist with perfect judgement and not prone to human error at all, a typical attitude for my age at the time.
A few months after starting to wear a helmet because people were being judgmental, not because I thought I would ever need it, I got into an accident where I went flying off my bike. Short story, it saved my brain.
Ya ya, this is anecdotal, but what was important about that experience for me, is it made me realize that my perceptions of safety were totally off. Our own control over the world is actually minimal, and even we fail despite how perfect we think we are at assessing the situation.
I was stupid. Being a cyclist wasnt experience enough for me to assess my safety, I needed a couple of near misses to realize how wrong I was. I needed to physically experience how my head deals with its momentum and pavement. I needed to experience how flying through the air face first with my arms extended to cushion the blow results in my back hitting the pavement followed next by the back of my head. Some people need to learn these things through experience.
If I were to assume everyone was as dense as I was at the time, I would counter with something like "until you've had enough experience being in accidents and thrown into objects, your intuition regarding the safety of that activity is suspect"
I didnt used to listen to people like me either!