[Profpat]

I forgot to mention Scott, that I think the outside human body is made up of 3.

The last page of my Idea shows my good looking grandson and 3 circles superimposed on him.
I think that is a basic model for the skull and face.

Also we have 2 eyes and 1 nose
2 ears and 1 mouth
2 nipples and 1 navel
2 lungs and 1 heart
2 kidneys and 1 liver
2 arms and 1 upper trunk
2 legs and 1 lower trunk
I'll let you do the sex organs.

We have left/right symmetry, not top/bottom. The Venn diagram also has left/right symmetry.

Later,

Pat