@thomasfuchs it’s a kind of religion. There is no persuading people.
For myself, when I was 28, I fractured my skull in a not very fast accident when I wasn’t wearing a helmet. I spent 3 days in hospital and 2 weeks off work.
I’ve worn a helmet ever since and have many times since banged my head at least as badly but have never had a fractured skull again 🤷♂️