When I lived in Bermuda (I think the population was less than 65k people at that time) a huge number of people rode bikes/scooters.
You NEVER left your helmet on your bike. It was either locked up in the bike box or you took it inside with you (your friend's house, a restaurant, whatever). You could never leave a helmet out in London either.
Here in Chiang Mai, a city with far more people than Bermuda, many people just leave their helmets with their bikes, unsecured.
I don't know about Bermuda, but I remember a time when London was a lot more high-trust. Maybe with the sheer number of people there it was never at Thai levels, but it was certainly more then, than it is now.
I miss that

