Now when he watches superstar Shah Rukh Khan dying on the hospital bed, Karan wishes the film ended in a different way.
The 41-year-old, who made his directorial debut with "Kuch Kuch Hota Hai" in 1998, admits that he made mistakes and conclusion of "Kal.." was one of them.
"Every film is a new mistake. When I see 'Kuch..', now I feel what a ridiculous story, when I see 'Kabhi Khushi Kabhie Gham', I think it is 35 minutes too long, 'Kal..', I wish I had changed the end..., 'Student of the Year', I wish it had more of emotional intensity. So, every film is a new mistake,` Karan told reporters post press show of `The Lunchbox` here.
The son of late producer Yash Johar said that his father had a major role in changing the conclusion of "Kal Ho Naa Ho" that also stars Saif Ali Khan and Preity Zinta.
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"It was my father's decision to show him (Shah Rukh) lying on the hospital bed. I was ending it far more differently, but he said 'Agar bada star ho toh usko marte huye dekhna chahiye, audience ko rona hai', (if it's a big star, we should show him dying as the audience wants to cry),` said Karan, who will direct another film next year.