Robert Downey Jr. walks out of interview after being questioned about his drug past

Memo to any journalist who's lucky enough to land one-on-one time with Robert Downey Jr. while he's out promoting his new film Avengers: Age of Ultron: Keep the conversation strictly professional.

One unfortunate interviewer found out the hard way when his questions got a bit too personal. Robert, 50, was patient enough during the political questions but when the interrogation turned to his past drug use, the actor lost it and walked out.

Watch the ultimate offending moment in the video above.

Robert had a well-documented drug problem for years, and he's spoken openly about it in the past. Clearly he's moved on, and he'd like the rest of the world to do the same.