Ethan Hawke opened up in an interview about the substance abuse that claimed so many of his colleagues, especially River Phoenix. Ethan Hawke made his breakthrough as an actor in Dead Poet’s Society in 1989. Since then, we have seen Hawke age gracefully across his starring roles, including Richard Linklater’s groundbreaking Before trilogy, where filming spanned 18 years. In a pre-turning-50 interview, the actor opened up about his friendship with River Phoenix and why it prevented him from ever moving to LA. Hawke learned acting as a ‘craft’ rather than to be a ‘celebrity’The 54-year-old actor…