Some kind of sticky crud forms on the lip of my coffee cup as I sip from it first thing in the morning. I usually just lick my thumb to wet it and wipe the crud off. This morning, though, I paused just long enough to wonder: What is that crud?
The obvious answer is: Coffee. There must be little bits of something in the water that makes it coffee, and those little bits are somehow congealing on the lip of the cup as I drink. No idea why. Might be wrong about that.
The only other answer I could think of was: Might be bits of sloughed-off skin from my lip adhering to the scalding-hot rim of the cup. That’d be pretty gross. I gotta stop thinking about shit like that.