Wow.

Is this now a helmet discussion?

I ride half my time in CPH, in which 5% of people wear helmet ... and that's a generously high estimate.

I ride half my time in England, which is similar to the US in many ways ... and roughly 50% of people wear a helmet.

I rode 3 months without a helmet before my possession arrived from Germany, now I ride with a helmet.

To be honest, I don't notice the difference and I doubt that most Americans would.