This is mostly personal opinion.
In my view, the main difference from apes (or other apes), is that we are a eusocial species. I see the larger brain, language abilities, etc as adaptations for social living. Our social brain allows us to interact with social constructs – such things as football games, mathematics, law, art.
I doubt that anthropologists and paleontologists will ever be able to fully trace our past, so we might never get beyond guessing.