In 1979, 18-year-old Austrian apprentice Andreas Mihavecz was locked in a police holding cell and forgotten after officers assumed someone else would release him. He remained trapped there for 18 days with no food or water, growing weaker while he listened to sounds from outside and realized no one knew he was still inside.
To stay alive, he licked condensation from the cold walls and lost a huge amount of weight as his body slowly consumed itself. When authorities finally opened the cell, they found him skeletal but still breathing, and he later recovered and became known as the person who survived the longest documented period without food or water.