Imagine being under a lot of stone age people and you are the only one who thinks something like "Hey I am a human being, and now I am thinking about this and that and maybe I change myself to become a better person". You would see the world in a totally different way. No one would understand your behaviour because nobody thinks about himself (self-aware) or sees the world as you do.
So my question is: How did we get self-aware? how did we develop this "feature"? And why did we develop this, how could the nature think that this would be an advantage?
There has to be a small "jump". I mean, somebody has to be the first who thought about himself. Either you know (or think about) that you are a being or you don't. So you can't just be a little self-aware right?