In Warren Zanes' new book, Petty: The Biography it is revealed that after his divorce in 1996, Tom Petty developed a heroin habit. He fell into a deep depression as a result of not being able to keep his family together and having been cut off from communicating with his wife. Moving into a new house on his own, and The Heartbreakers being on a break at the time, Petty found himself with a lot of free time on his hands. And having been around people like Howie Epstein who was a heroin user, the rest sort of fell into place. Cocaine is a strong drug and it can be used socially. The reason Tom has kept this a secret for so long is that he felt that talking about hist drug use would set a bad example and would lead people to think that escapism through substances is a good idea. When Warren Zanes proposed the idea of talking to Tom about this, he promised him it would be a cautionary tale rather than romanticizing drug use.