Tracy, California - Most people end up with arm hair that doesn't grow more than about a quarter of an inch in length. For Macie Davis-Southerland, though, her arm hair was long enough to score a record.

Few of us really put any thought into our arm hair. It's just kind of there. It exists; it provides us with a little bit of insulation, and we mostly ignore its presence on our arms. Despite her eventual achievement, it was much the same for Macie Davis-Southerland, who has the longest arm hair in the world.

So, what's behind Macie's extraordinary world record? How did she find out, how did she grow her arm hair so long, and just how long did it get? Let's take a deep dive – it's an interesting story!

California native Macie Davis-Southerland recently took home a world record for having the longest arm hair ever recorded. It was a bit of a fluke, too, as Macie had barely noticed her bizarrely long arm hair until people started commenting on it in high school – up until recently, she had assumed that it was just a strange quirk and nothing to really think about.

Talking to Guinness World Records, who officially awarded her the record, Macie said that she was at Disneyland with a friend, and it was her friend's brother who initially brought her attention to just how long her arm hair had got.

"I was at Disneyland with my best friend Kaylee's family when her older brother pointed out a hair on my arm," she explained. "He was telling me that I had an extremely long hair, and his original thought was to pull it!"

Considering that it is only a single arm hair that's so curiously long, it's lucky that he didn't pull it out. Instead, Macie continued to grow out her arm hair, hoping that maybe one day it could lead to something cool happening. When she realized just how much over the half-inch average it had got, she realized it was time for a world record attempt.

The problem was, though, that due to its intense size and length, it was easy to get snagged on things. This would sever it, or pull it out, making her have to start for scratch again and again.

Just last year, Macie managed to get the world record for the longest arm hair ever, at a whopping 7.24 inches in length. After more than a decade of trying to grow out her arm hair and beat that record, she had achieved her goal. It was a moment of jubilation, of great happiness.

What was so extraordinary was that she had refused to tell many people so that she could keep it as secret and hidden as possible, only revealing her quirky goal if it was truly a success. Even now that she has achieved it, she wants to break her own record time and time again.

In a particularly heart-warming moment, Macie revealed just how touched she was by her grandma's reaction: "My grandma Betty can’t stop laughing when we talk about it, and it makes me smile knowing that she gets a kick out of it."

"None of my other arm hairs come even close to being as long," she said. "They're all a normal length for an arm hair... My family and friends closest to me think it's the most amazing and hilarious thing."

Arm hair is some of the slowest hair on your body, growing at only about half an inch a month. Now, that doesn't mean that if you just leave it, it will end up insanely long, of course (after all, you would have noticed that!). Instead, your arm hair generally reaches a length at which it begins to fall out or simply stops growing, thereby keeping the length of your arm hair generally the same all the time.

Ultimately, arm hair is one of the slowest-growing hair types on the human body. Moving so insanely slowly, you couldn't be blamed for thinking it doesn't grow at all – just don't shave it off, or it'll grow back thick and weird!