I have developed this habit of scraping the underside of my chin with my fingernail absentmindedly.

Several times I hadn't seen the darn thing (now things) until to my horror they were highlighted in the daylight exposed in my car's rear view mirror!

So I have this theory they wait patiently just under the skin to emerge strong and mature when it would most embarrass me, as revenge against my tweezers. LOL.