Tamasha is about the journey of someone who has lost his edge in trying to behave according to socially acceptable conventions of the society. The film is based on the central theme of abrasion and loss of self that happens in an attempt to fit in oneself back.
All stories are same and yet one needs to find their own story. But before you start the journey of creating your own story, one must free oneself from being a character in stories created by other people. Ved(Ranbir Kapur) is one such character suffering from bipolar disorder who realises that the end to his suffering is to create his own story.
Ved and Tara meet accidentally in Corsica, France and decide to spend the next 7 days together without revealing their true identity or without any promise to meet later, ever. Tara eventually falls in love with Ved and goes to find Ved after 4 years, and helps him to find his true story where he belongs.