Inside your skin?

[jenk]

This made me smile:

When it comes to how we treat our birthday suits, it seems, we are like 2-year-olds: more concerned with the wrapping and ribbons than with the present itself.
[...]
With its rich array of sensory receptors, skin is the bridge between private and public, wary self and beckoning other. Through the touch of its mother, a baby learns it is loved.
[...]
Our skin bends over backward and puts itself out and saves face and rejuvenates and exfoliates for us, year after year, but time takes its toll. With age it gets thinner, losing collagen and elastin and the fingerlike anchors that help keep our epidermis in place. The connective fibers that remain become stiffer and weaker and more chaotically cross-linked. Chronic sun exposure can hasten the breakdown by 10 years or more, which is why come next summer, I plan to go spelunking.
- Natalie Angier, writing in The New York Times