"If you come to ___ not understanding who you are, it will define who you are": Oprah Winfrey
I believe the answer is:
fame
(Other definitions for fame that I've seen before include "Renown, celebrity" , "''... is the spur that the clear spirit doth raise (Lycidas, John Milton)" , "Celebrity; stage musical" , "Repute" , "14 [BOWIE] recorded this" .)