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.
"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.