The 'last' living caveman, one day decided that he doesn't want to die alone, and so with what little hope he had left, he ventured out of his caves, in a search for other living cavemen. Hoping for a female specimen, ofcourse.. But the dinosaur's have overtaken the world, and he hasn't seen a living person for a very long time.. So basically there you are - the caveman dude trying to find other cavemen.