Ever since his emergence with a stunning performance as an abused stepson in “This Boy’s Life” (1993), actor Leonardo DiCaprio has been expected to achieve greatness by critics and the public alike. Luckily, DiCaprio has largely met expectations, thanks to an Oscar-worthy performance as a mentally challenged teenager in “What’s Eating Gilbert Grape” (1993) and as a troubled teen in “Marvin’s Room” (1996). While he became a bona fide star, nothing prepared him for the life-changing celebrity he achieved with “Titanic” (1997). Almost overnight, DiCaprio went from a popular actor to an