Congratulations to Mark. I am impressed by both his competitive accomplishments and his longevity. It looks like his is a streak of legitimate runs. I remember a story from years ago about Ron Hill, the great British distance runner, who was so obsessed with his own streak that he did things like hobble around the track on crutches and jog in a jail cell after a drunk driving arrest.
I am not one of those who thinks that Mark is crazy. I passed the 30-year mark of my own streak earlier this year. I didn't set out with any notion of maintaining a streak. Running is simply something that I do because I enjoy it. (I've seen the Let's Run threads on why masters still run and race; that's my simple explanation for why I do both.) Like Mark, my runs have all been legitimate. I run unless I am too sick or too injured to do so. Fortunately, the last time one of those was the case (injury) was in 1978.
I am headed out for my daily run. If I get hit by a truck, that will be the end of my streak.