That explains a lot about some posters in this thread...... ............... Head injury sufferers, often have radically changed personalities afterwards. You don't want that.
I'd spent more than 20 years in the Navy and as a tall guy had banged my head countless times on hatch combings and other obstacles - helmets weren't and still aren't part of the uniform and weren't part of my cycling wardrobe either.
However, as I passed my three score years and ten and speed of reaction and agility lessened, I was wondering when in my approaching dodery state, I should for my own peace of mind, get myself a 'lid'.
Then on a lovely countrylane ride last October I failed to notice the adverse road conditions and off I came resulting in a double pelvic fracture and nasty bang on the head. Fortunately a full recovery and back on the bike after a couple of months BUT now wearing a helmet in recognition of my stupidity at not paying attention and a recognition of the passing years.
Some will argue that one such accident in 70+ years of pedaling is hardly justification for now going 'lidded' and a good portion of me would agree with you.
Thank goodness helmet wearing is a choice in this country though and at the moment my wife is more at ease when I cycle off - and that's what counts for me, but each to their own.