Who's that monkey in the mirror?

When I look in the mirror to shave every few mornings or so, I know I'm looking at a reflection of myself and not another human who happens to be doing just the same thing that I'm doing at the same time. Even though I can be a bit shy in person to person contact, I am not afraid of eye contact, nor was I when I was a child, which allowed me to make the connection that the image I saw in a mirror was really me many years ago. Chimpanzees, bonobos, and oranguatans can recognize themselves in a mirror as well (gibbons and capuchin monkeys can't, even though they can use mirrors in different ways), but gorillas ultimately fail the mirror test. Why should this be? The video below might give you a clue, and I'll deliver the answer in full tomorrow;