Now, imagine a sheep in all its woolen finery going through a similar experience, except rather than having a few bath-free days, we're probably heading towards a bath-free year, and its oil-soaked coat hasn't been cut in that entire time. Finally, picture what it would look like if someone came and collected the greasy substance that had accumulated in the woolly locks, and put the resulting gunk into a jar.
Hint: It would look like this.
This is lanolin, the greasy stuff secreted by wool-bearing mammals to help shed water from their coats, squeezed from their harvested wool and bucketed for many uses, including shoe polish, barnacle repellents and rust-proof coatings.
Oh, and also you smear it on your face.
"But I'd Never Use Tha-"
Do you use shaving cream? Shampoo? Well then there's a good chance you've had this stuff on your face and around (or in) your mouth. And as for the ladies (and the more adventurous males out there) you've likely had much closer contact with lanolin than you'd care to think about. In fact, if you've ever used lipstick, lanolin is the stuff that makes it greasy and sticky.
Maybe she's born with it, maybe she's got sheep grease smeared over her lips.