The perfect casting: Director Ayan Mukerji proved that he knew a thing or two about casting the right actors in his film. The movie united Deepika Padukone and Ranbir Kapoor, two of Bollywood’s most talented actors, along with Kalki Koechlin and Aditya Roy Kapoor in one frame. The fabulous four, who formed the core friendship group, had such great chemistry with each other. Padukone as the nerdy, class-topper Naina Talwar who goes on an impromptu trekking trip with her unfamiliar school mates was pitch-perfect. Director Mukerji also knew how to capitalise on the immense chemistry between the once loved-up couple Kapoor and Padukone. The handsome pair had gone their separate ways in their personal lives after a doomed affair, but they taught us that being colleagues after a break-up isn’t a recipe for failure. Who said exes can’t remain friends? Plus, Koechlin as the kooky and nutty Aditi who secretly harbours a crush on her rakish best friend Avi (Kapoor) is also an interesting tangent that made this movie enjoyable.