The star of what seems like a thousand action movies, starting with 'Top Gun' and continuing to the present day with the 'Mission Impossible' franchise, Tom Cruise is famous within the industry for insisting on doing his own stunts. The greatest stunt he may ever have pulled, though, is picking a cool and snappy sounding stage name instead of going by the one he was born with.
If you could find Cruise's birth certificate, you'd see that he was born Thomas Cruise Mapother IV. Considering there were presumably four men with the same name who'd been born consecutively by that point, the time was probably right for a change! The unwieldy and hard-to-pronounce last name got cut, along with the numerals. The first name got shortened, the middle name became a last name, and an icon of the big screen was born.