Anyone know any famous people before they were famous?

Knew a TikToker who I will NOT NAME as he would spend hours attacking me online and having his followers doxxing. He was a bit….. unbalanced before he was famous in that he would call people by slurs for fun, prank call a support hotline, film people in private moments without consent for Snapchat. And his TikTok nowadays is even more a dumpster fire. Anyone know anyone before they were famous and did they seem to change since it happened?