Depends on what you count as self awareness I guess. Wikipedia has it as "the capacity for introspection and the ability to recognize oneself as an individual separate from the environment and other individuals", and in the same article it talks about an experiment that suggests magpies have some level of self awareness. So by that I think it's safe to say "man", that is our species, have never existed in a state where we were biologically incapable of self awareness. We've had more cognitive capacity than magpies for longer than we've been homosapians.