How come we don't notice that awkward random hair until it's 2 inches long?

I’ll occasionally get a weird hair growing on my upper arm, or on my CHIN! (hello, I’m an xx with ovaries, Mother nature!) Luckily the one on my chin was fine and fair, so it wasn’t noticeable. But sometimes ones on my arm are monstrous. They’re freakishly long and somewhat coarser than my normal arm hair. I’ve seen this on other people so I KNOW IT’S NOT JUST ME!

What causes these freaks, and why don’t we notice them until they look like anacondas?

**Disclaimer: This only happens like once a year. I’m not a Yeti.