Infact Saif Ali Khan was not the first choice of Aditya Chopra, the director of Dilwale Dulhaniya Le Jayenge ( DDLJ)
Aditya Chopra, after assisting his father Yash Chopra in a number of films like Chandani in 1989, Lamhe in 1991 and Darr in 1993 wrote the scripts of several films including the script of DDLJ and he took 3 years to write the script of DDLJ.
Aditya Chopra initially wanted the film to be about a relationship of an Indian girl and an American guy, so he wanted to cast Hollywood actor Tom Cruise for the leading role of Raj. But his father Yash Chopra was not interested to cast a foreign star and so they decided the character Raj would be an NRI.
Later Aditya Chopra offered the role of Raj to Saif Ali Khan opposite Kajol but due to the unknown reasons and his commitments with the other films he declined the offer. It has become a great mistake of Saif, DDLJ became a big block-buster which was released in 1995.
Even Aditya Chopra approached Aamir Khan for DDLJ but he too declined the offer because he was not interested to perform romantic roles at that time.
Aditya Chopra wrote the script of DDLJ with a unique storyline, at that time most of the films were based on two lovers who run away from their houses when their parents object for their marriage. But in DDLJ, Aditya changed the theme and in his film the leading character Raj decides to get the permission of heroin's father at any cost without taking her away with him.
Earlier Aditya Chopra asked his father Yash Chopra to direct the film but his father asked Aaditya Chopra to direct the film by himself. Even Aditya's mother Pamela Chopra praised the script of the film, then Aditya Chopra decided to direct the film and DDLJ became his directorial debut film.
Though DDLJ received high success commercially and critically, Saif Ali Khan never expressed his repentance or regrets in front of media or in any interviews for rejecting the iconic role of Raj offered by Aditya Chopra, accepted it as a part of an actor's career choices.