&gt; Then why don&#x27;t you wear a helmet when you&#x27;re walking on ice as well?<p>Because bikes constrain falls. Millions of years of evolution plus my own personal practice means I&#x27;m pretty good at falling safely. But when I am wrapped around a bike, a lot of that goes out of the window.<p>Also, I&#x27;d like to see some stats on your &quot;not very likely&quot;. In 20 years of adult riding, I&#x27;ve fallen twice at low speeds hard enough to crack a helmet. And that&#x27;s not counting the time as a kid I knocked myself unconscious on a low-speed ride.<p>&gt; because you forgot your helmet<p>Is this a problem people have? When I&#x27;m not riding, I clip my helmet to my bike. This doesn&#x27;t strike me as a particularly challenging habit to develop. Maybe just keep necessary equipment together? That sounds easier than trying to decide whether the odds are small enough to risk traumatic brain injury.