Unable to talk until he was three years old, Albert Einstein, the man whose name came to be synonymous with genius, was initially suspected of being mentally retarded. Pictured above with his sister, Maja, Einstein fared abysmally as a schoolboy in Munich, Germany, and was dismissed by his teachers as slow and lazy. Mathematics was his sole strong point: When Einstein quit school at the age of 15, his teacher claimed there was nothing left to teach him.

PHOTO: BETTMANN/CORBIS