[Although] apes and humans share a number of important advanced cognitive abilities, they differ in one key respect: the extent to which humans can detach themselves from the world as they experience it. This allows humans to reflect on the world as they find it, to wonder wether it could have been otherwise. In contrast, apes (and certainly all other animals) have a much more direct, straightforward experience of the world. Their noses are thrust firmly up against reality.
The Human Story, Robin Dunbar