James Cameron praised Shah Rukh's performance and stated it as his favorite Bollywood film.
To give his 100% in movie, SRK used to spend time with the people having asperger's syndrome, used to watch the videos and used to read the books related to that mental illness to learn how they behave, talk and walk.
During a publicity outing, Shah Rukh Khan came to the US but was detained at customs for over an hour. People first thought this was a PR stunt but it was revealed that it was not. The film's producers were furious that their star was treated so shabbily, not unlike Khan's character in the film.