* Subjectivity: "Famous" is relative. What's considered famous to one person may not be to another.
* Changing Usage: Some people are primarily known by their first name at certain points in their careers, but later become more recognized by their full names.
* Cultural Differences: What's considered "normal" naming conventions varies across cultures.
However, here are some factors that contribute to someone becoming known by their first name:
* Unique Name: A distinctive first name can be memorable and help with recognition.
* Brand Recognition: Some people create strong brands around their first name (think Madonna, Oprah, Cher).
* Artistic Persona: In certain fields, like music or fashion, using a single name can enhance a persona or mystique.
* Tradition: Some fields, like royalty, often use only first names (e.g., Queen Elizabeth, Prince Charles).
Examples of famous people known primarily by their first name:
* Music: Madonna, Prince, Rihanna, Beyoncé
* Acting: Drew, Oprah, Cher, Woody, Reese, Goldie
* Writing: J.K., Stephen, Toni, Maya
* Politics: Barack, Hillary, Donald
* Sports: Tiger, Michael, Serena, Usain
It's worth noting that many people known by their first name may still use their full names in formal situations or for legal purposes.