Have you ever stared at your nipple and tried to will it to become hard?

[Mister Obvious]

I did this after noting that my nipple, which had just been hard a mere moment ago, was now soft and I realize I hadn't watched this transition take place. And it got me thinking about how strange the hardening and softening of the nipple is in a kind of 'matrix' viewpoint of things. So I tried to make the nipple hard again by staring at it, and I think it almost worked, but I gave up.