London: Hollywood heartthrob Robert Downey Jr, who was jailed twice for drugs offences in the late 1990s, says that the prison stints did not teach him anything.
The `Iron Man` star compared the experience to being at school or on a film set, in an interview to a leading magazine.
The actor says that he is astonished that his reckless lifestyle didn`t get him into trouble sooner.
"I do think there`s something divine about large-scale humiliation, but no, it never worked for me. It never produced enough of a blow back for me to catch the drift," said the actor.
"Jail didn`t help me any more or less than anything else. But I know I created that experience for a reason, and I`m only just starting to understand those reasons. I can`t believe I stayed out of the pen for as long as I did," said Downey Jr.
The 46-year-old actor insists conditions in jail were not much different from being at school or on a film set.
"And I didn`t mind it inside really, it wasn`t so bad.
Listen, a prison is just like a public school. Did you ever go on a film set on location? It`s just like prison. Have you ever been in a bad relationship?
"It`s just like having a cellmate who wants to kill you. Have you ever been in a street fight? It`s just like chow-time meal time. Have you ever been to a rave-up? It`s like a yard riot. I wouldn`t wish it on anybody, but it neither fazed me, nor changed me, nor informed me, but maybe it toughened me up a little bit," said the actor.