First things first - No heroine on screen has ever looked as gorgeous as Deepika Padukone in Karthik calling Karthik! To quote my friend, "Deepika Padukone, for once, steals the thunder from Farhan." I would moderate that a little because Farhan has done his part like a seasoned veteran. Watch the contrasting manner in which he walks, bends and talks to know what I mean.
The movie is part romance (1st half) and part thriller (2nd half). You get to experience all primary emotions - Fear, Joy, Love, Sadness, surprise and anger in the space of a little more than 2 hours. Full credit to Vijay Lalvani for the story, screenplay and direction. Costume design and casting is just bang on. Clothes for Farhan (Karthik) - when he is diffident and when he exudes confidence reflect the same to a T! Deepika (Shonali) carries herself off adorably, delectably, sensuously and the list can never end!
The story is very realistic, laden with a lot of symbolism (the use of Rubik's cube throughout is a masterpiece I would say) and doesn't need too much masala for embellishment. The humor in the first half is very natural and the lead actors should be appreciated for their timing. The sequences in the second half are intelligent, especially Karthik's reasoning to find a solution to his woes.
Expectations were perhaps too high from the music (by Shankar, Ehsan and Loy). If not for the manner in which the songs have been shot (especially 'Uff teri ada'), it is not great. The background score in most parts is effective (considering that it matters a lot in a thriller) but occasionally it drowns out the dialogues. Technical brilliance manifests itself in the manner in which lighting has been used.
Perhaps the sub-conscious minds in all of us really has the potential to elevate us and help us scale new heights in the quality of our lives. The phantoms of the mind are indeed very difficult to comprehend, let alone control.
Go watch Karthik calling Karthik. It deserves a visit to the nearest movie hall...