"The 100-Year-Old Man Who Climbed Out the Window and Disappeared" is a novel by Swedish author Jonas Jonasson. It follows the adventures of Allan Karlsson, a centenarian who escapes from his nursing home on his 100th birthday. His journey leads him to a suitcase filled with money, a group of criminals, and unexpected friendships. The story intertwines Allan's past, revealing his involvement in significant historical events, including interactions with notable figures like Harry Truman and Mahatma Gandhi. The novel combines humor and absurdity, showcasing Allan's unique perspective on life and the absurdities of the world around him.