Last week challenged the notion that I have thick skin. After eight years and change in New York, I might have believed (before last Monday) that I’d built up a hardened hide. Alas…not so much.

The saying “thick skin” probably began by referring to calluses. The extra layers of tough epidermis stacked over a wound or perhaps a patch of skin that was a little more pampered than the rest—until it wasn’t.

Of the dozen or so times that friends comforted me with the promise that my skin would thicken—just keep going—for some reason, I thought of reptile skin. Maybe because I grew up in an Army home, I associated protection with camouflage and armor, like reptile skin.

Saturday I biked over this chalk drawing down by Battery Park. With all this fresh on my mind, I saw scales. The hexagonal city bricks transformed into cold-blooded skin cells with shades of green that blended into the surrounding Spring bloom.

Reptiles molt, I thought as I pedaled around this drawing. Reptiles shed their old skin to become something anew. I imagine those first few moments in their new skin were careful ones, creeping forward, feeling everything acutely. Like when the wind first hits the skin under a curled-off callus.

The drawing must be gone this morning after all this rain. Making me see that skin—thick or not—can be as ethereal and transient as chalk on cement. To evolve, we need different skins for different days.