While scientists are unsure as to which ape is our common ancestor with our closest relatives, e.g. chimpanzees, research points to the genus Pan. As modern chimpanzees, gorillas, bonobos, and so on, have certain degrees of self-awareness, it’s likely our common ancestor possessed some as well.
As there’s no evidence that chimps possess spontaneous conceptual-self abilities, nor did our common ancestor. However, modern apes do have a modest amount of private-self awareness. For instance, chimpanzees are known to deceive each other (and their zookeepers!), often in clever ways.
Given this, our common ancestor likely imagined how the world could look in the very near future, albeit in a highly limited way.