Before he was famous, Robert Downey Jr. had a troubled childhood. His father, Robert Downey Sr., was an actor and director who often allowed his young son to watch him work on set. This early exposure to the film industry had a profound effect on the future Iron Man star, and he developed a strong interest in acting. However, his parents' volatile relationship and substance abuse issues led to a chaotic home life for young Downey. He began using drugs at age eight and by the time he was 13 he was already addicted to cocaine.
Downey's addiction problems continued into his teenage years and twenties, derailing his promising acting career several times. He spent time in rehab and even spent a year in prison in 1999 for drug-related charges. Finally, in 2003 he made a comeback with the hit movie Kiss Kiss Bang Bang, which jumpstarted his Hollywood career once again. Since then he has gone on to become one of the most successful actors in Hollywood thanks to roles like Tony Stark/Iron Man in the Marvel Cinematic Universe films.