Charles Darwin set off as ship's naturalist on a voyage to South America and the Galapagos Islands.
James Joyce left his family, his church and his country for the European continent, in order to become a writer.
By 22, Swiss psychologist Jean Piaget received his Ph.D., published 20 articles, and wrote a philosophical novel that outlined many of the issues he would explore during his career.
Caresse Crosby became the first person to patent a brassiere, which was made of two handkerchiefs and ribbon sewn together.
The Greek orator Demosthenes, orphaned at age 7, took his guardians to court when he was 22 for misusing his inheritance. He won the case.
Olympic runner Herbert James Elliott, ranked by many as the greatest mile runner ever, retired undefeated at 22.
U.S. swimmer Mark Spitz won a record 7 Olympic gold medals.
Inventor Samuel Colt patented the Colt six-shooter revolver.
Cyrus Hall McCormick invented the McCormick reaper, which allowed one man to do the work of five.