Liddy, My remark about the felt hat was simply an effort to put into context helmet usage with an activity that you are familiar with and stress the point that it's your/my head, your/my decision... not a sarcastic barb. In retrospect I can cringe at how I've ridden horses... galloping through the woods, wearing only cut off jeans while bareback.
Collective wisdom is one is better off wearing a helmet than not for the types of bicycling accidents that most often occur. Crashing while cycling is a bit different from crashes in horseback riding or motorcycling. Speed is often slow enough that there isn't the sliding and/or rolling available to scrub off energy, at least in my experiance. While the head may not may the initial contact with a solid object, it most likely will make subsequent contact during a crashing event and I'd like to minimalize neural damage.
Brad