It's a mental image.  A way of looking at things.  I'm not sure how I should describe it--maybe just, sometimes I don't fill out all my skin.  Like, the me-ness that is truly me contracts and is only a ball of flame centered in my gut--it doesn't go out to my fingers or down to my toes, or up to my face--the ways in which I interact with the world are on autopilot, gone blank, frozen in calm.  You who look at me don't see me.

It's intentional, I suppose.  I don't really want you to see me, because then you would know me.  And then you could hurt me.  So I am tough like old boots, resilient, flexing in the ways I'm accustomed to, showing you only what is time-tested by etiquette and society and habit--showing you things, if I must, plainly, unadornedly, in a way not worth taking a second look at, really.

And then, sometimes I fill my skin, if I love you, if I want you to know me .  And I am tough like old boots--comfortable, loved, worn-in, supporting, sturdy, loyal.  I will go with you wherever you lead, and take you wherever I go.