The actor can currently be seen in Barfi! opposite Ileana D'Cruz and Priyanka Chopra.
He told the Hindustan Times: "I have a personality problem. I am extremely shy; an introvert and a private person. I lead a normal life when I am not working. I am not on Facebook, Twitter or anywhere.
"I like it this way. You'll see that I don't have a PR manager to take care of my image, because there isn't any image that I have set out to create."
The 29-year-old added: "I am here for the long run, so I don't want to feel successful so early in my career. Also, I am too young to feel success and failure. I want to grope in the dark, struggle and work hard. At no point do I want to put up my feet and feel that I have arrived."
Kapoor said last week that he wanted people to come to see the film rather than just praising him.
He has also confirmed that his next project will be acclaimed director Abhinav Kashyap's Besharam.
Watch the official trailer for Barfi! below: