I used to tell that joke moderately often.
My wife and I were riding our mountain bikes on a country road a few years back. The ride had been scenic and uneventful when suddenly, this enormous and ferocious looking dog with red eyes, huge teeth dripping saliva, and malice emanating from head to tail came charging at us. My wife is perfect in many ways, but being a fast bike rider is not one of them. It was clear that there was no way she could go fast enough to get away from the dog. She said the first thing to come to her mind was the above joke about the bear and knew that I could easily ride faster than her.
My experience was quite odd and I've never experienced anything like it before or since. Something farther down my brain stem, something instinctive and primal, took complete control of my body. My conscious self was suddenly along for the ride, not only having no control, but not even having any input. I heard my voice yell, "Go! Go!" to my wife and watched myself position my bike directly between her and the dog in what was clearly a protective maneuver. I was quite surprised and remember thinking, "I wonder what my body is going to do next?" as the dog closed in.
Fortunately, my wife under these particular circumstances is actually quite a fast bicyclist. She accelerated her bicycle through the speed of sound nearly instantaneously and the resulting sonic boom left broken windows in three counties. Her superhuman effort left me in the dust, but fortunately I was able to go fast enough to get out of the dog's range as well.
I don't tell the bear joke very often anymore. That experience made it too close to home.
My wife thought I was pretty chivalrous. I haven't bothered to mention that it wasn't "me" that was chivalrous, at least not the "me" that's writing this post or the "me" that she usually interacts with. It was some internal alien that was chivalrous, a "Mr. Hyde"-like creature who is apparently encoded in my genes to emerge when my wife and perhaps other loved ones are in imminent danger. We live pretty safe lives and that was the most danger in which I've ever seen any of my loved ones, so the alien has always been dormant except this one time.
One thing I read about the Aurora shooting that brought tears to my eyes was the following:
In final acts of valor, Jon Blunk, Matt McQuinn and Alex Teves used their bodies to shield their girlfriends as accused madman James Holmes turned the Aurora cineplex into a shooting gallery.Out of the 12 people who died, (at least) three did so for altruistic reasons. Amazing!
I've always wondered if I would have the courage to do something like that. If the emergent alien comes through, for sure. If not, who knows?
Whether their actions were conscious or instinctual, they were heroes either way.