Imagine not getting a haircut for over 30 years. Sounds like the start of a wizard origin story, but for Xie Qiuping, it became a world record. When she finally cut her hair at age 44, the result was a mind-bending 5+ meters of hair, earning her a place in Guinness World Records.

This video from TED Ed explores the tiny factories under your skin—hair follicles and the cells that crank out strands of keratin like microscopic 3D printers. On average, scalp hair grows about 15 cm a year and keeps going for 5–7 years before the follicle shuts production down. That usually caps hair length at around one meter, unless genetics, hormones, and sheer follicle determination decide to go full Rapunzel.

The video also explains why eyelashes stay short (so you don’t accidentally grow curtain bangs over your eyeballs), how hair transplants work, why hair turns gray, and what actually causes baldness.

So if you’ve ever wondered just how long your hair could grow, assuming you resisted the urge to trim it for years, this video has the answers, straight from the follicle factory.