Aamir Khan is such a big name in India that he could not go in and out of the house that the shoot was taking place in without arousing huge public interest. So he and his wife Kiran Rao, who is also the director, actually stayed in the same house for the entire duration of the shoot.
The movie uses two Hindustani classical renditions. One is Siddheshwari Devi's dadra "Paani bharan aaye" in Raag Khamaj. The second one is Begum Akhtar's rainsong thumri "Ab ke saawan" in Raag Tilak Kamod which blends beautifully in the backdrop of Mumbai monsoons.
Saif Ali Khan and Akshaye Khanna were highly considered for the lead role of Munna. Ironically, both of them starred alongside Aamir Khan in Dil Chahta Hai (2001). However they were not selected because Kiran Rao preferred someone younger for the role.
Varun Dhawan auditioned for Prateiks role and was rejected.
Aamir Khan, who is known to have played characters that are almost half his actual age (including a college student in Rang De Basanti (2006) and 3 Chàng Ngốc (2009)) plays a character closer to his actual age, with graying hair, in this movie.