When I was small , we had pulled into the front line of cars on a ferry boat . As the ferry began to move forward , Dad was concerned that it was going to run into the piers along the side , and began pulling hard on the car's steering wheel .

I'm guilty of ducking a bit sometimes, even when the height of the entrance is noted clearly, since I honestly can't remember the measurements of my car, though totally trusting intellectually that my car will fit. Ducking due to the illusion I'm about to be decapitated is a natural instinct that I allow myself. Yep, I know the roof of my car is padded, just in case, too!

I'm glad I still have some human instincts. I catch myself ducking under branches on my bike too, but for good reason. Since I ride the same path every day, I can gauge just how far down I have to duck my head. Sometimes I'm too brave and get leaves in my hair.

thanks for the wonderful laugh

Instincts handed down to us through millennia of evolution don't change easily. To react to threats that aren't actually there (false positives) vs. ignoring what may very well kill you, tends to winnow down the gene pool. You keep ducking ... it just may preserve your future generations!