Yeah, I had similar thoughts -- my most recent head-whacking bike accident involved, er, me and my house, and God knows it's not like I'm not an experienced cyclist with a lot of miles under my tires! Opportunities to whack one's noggin into large dense stationary objects abound.

Also, I can't help noticing that locally, the in-town car-bike accidents which have been fatal, in the last few years? All involved a cyclist who wasn't wearing a helmet. (We did have one fatal accident where a woman road cyclist was wearing a helmet, but she fell under a log truck out on Territorial...and there ain't much a person can do against a log truck.)