When Shah Rukh Khan drops Kajol at the end of "Ruk Jaa O Dil Deewane," director Aditya Chopra did not tell Kajol what was going to happen, so that her reaction would be genuine.
Aditya Chopra had lots of trouble filming the scene where Raj (Shah Rukh Khan) jokes with Simran (Kajol) about the previous night. The reason was that every time Shah Rukh Khan would open his shirt, Kajol would not stop laughing. The pictures of the lips on the chest were drawn by Kajol.
Shah Rukh Khan's friends in the film, Karan Johar and Arjun Sablok, both later went on to become successful directors.