There's no proof of this, but I'd bet the cavemen dreamed of woolly mammoths, saber tooth tigers and dragging some pretty girl off by her hair.
(I; 'd bet; the cavemen dreamed of woolly mammoths, saber tooth tigers and dragging some pretty girl off by her hair) (the cavemen; dreamed; of woolly mammoths, saber tooth tigers and dragging some pretty girl off by her hair)
I the cavemen
'd bet dreamed
the cavemen dreamed of woolly mammoths, saber tooth tigers and dragging some pretty girl off by her hair
of woolly mammoths, saber tooth tigers and dragging some pretty girl off by her hair