unremarkable high school career. so you weren't even that good to begin with. >> right. >> and at 66 you said i want to relive this mediocrity. >> try this again. >> reporter: why? >> it's fun. it's like going to high school again with nothing to study. ( laughter ). >> reporter: nothing to study but the physics of gravitational potential energy and pain minimum. >> that's a jump right there! >> reporter: but don says it's well worth the aches. >> it's a rush, exhilaration, when you clear a bar. >> run, don, run! >> reporter: at a meet last year, don cleared nine feet, one inch. no octogenarian had ever done such a thing. and then just moments later, set another record-- oldest man to be a human centrifuge. and don says he's not done setting records. in fact, he told me he plans to keep fit and keep at this until he's six feet under, which by my calculation, is still about 15 feet away. steve hartman, "on the road," in princeton, texas.