Sugar, our 9 week old Bichon puppy is teaching me far more than I am training her. She cannot read and has little intellect (bless her) yet she lives as Suzuki suggests in Zen Mind Beginner's Mind. "If we are like the frog, we are always ourselves." But instead of frog, read "9 week old Bichon puppy" (or any animal, really) and you'd be right.
Zuikan was a Zen master who always used to address himself. "Zuikan?" he would call. And then he would answer, "Yes!" "Zuikan?" "Yes!" Of course he was living alone in his small zendo and of course he knew who he was, but sometimes he lost himself. And whenever he lost himself he would address himself, "Zuikan!" "Yes!"
I know this is what Sugar is doing when she chases her own tail, or when I chase mine. We're checking out the certainty that we exist.