She spent 130 days alone underground. Her brain erased half of it. In 1989, Italian interior designer Stefania Follini voluntarily sealed herself 30 feet underground in a New Mexico cave, cut off from all sunlight, clocks, and human voices. She lived alone inside a small Plexiglas enclosure, with no way to track time whatsoever. Her only companions were two mice named Giuseppe and Nicoletta, a guitar, and a computer. Without any external time cues, her biological clock completely broke down, shifting from a 28-hour day to eventually a 48-hour one. She slept around 10 hours and stayed awake 20 to 25 hours at a stretch. Her meals spread further and further apart, she lost 17 pounds, and her menstrual cycle stopped entirely. When she finally emerged on May 22, 1989, she guessed the date was around March 14 — believing only two months had passed instead of four. Having spent 130 days underground, she broke the women's world record for longest cave isolation. The experiment revealed something deeply unsettling: without sunlight, the human brain simply cannot keep time.