Can't resist taking this bait, but I feel like the consensus is pretty much that as an individual, choosing to wear a helmet will make you safer, and as a society, mandating bike helmets (and other measures that will cause people to use transportation methods that are more dangerous to others) will make everyone less safe.

Of course, it's hard to prove. But I think you'll generally find that, if you compare the number of injuries/deaths while cycling in countries with mandatory helmets per km will be higher than it is in the Netherlands, where they are not mandatory.

I can understand, I’ve had some awful bicycle accidents while not wearing a helmet and the helmet would have made no difference. My knees, hands and elbows have been through a lot but I have never hit my head. Even while skateboarding the one time I hit my head a helmet would not have helped. In hindsight I should have worn knee pads a lot more often but then I wouldn’t be able to tell if it’s gonna rain or not from the feeling in one of my knees :)

However if I had to ride on a public road with cars zooming pass me recklessly I would absolutely wear a helmet on a bicycle.