Referring to director Pradeep Sarkar, Saif reportedly wrote: "This 'Bong' has made me work for 32 hours continuously!"
To which, Chopra advised him to "run...run...run" - and it actually was running that Saif did on the last day of shooting.
The film, which is an adaptation of Sarat Chandra Chattopadhyay's classic and also stars Sanjay Dutt, Raima Sen and newcomer Vidya Balan, started shooting early October in Darjeeling.
Saif's fondest memory is shooting in the same train that his mother, Sharmila Tagore, featured in for the hit song "Mere Sapno Ki Rani Kab Aayegi Tu" from the film "Aradhana".