Jimmy's character in Look Back in Anger is the "angry young man."
Jimmy is upset at the world around him. He feels he is denied his rightful place in British society because of his working class heritage. He finds phoniness repugnant. It is in a world that says that the class system is gone, but still operates under it. Jimmy cannot accept that someone of his talents is left to occupy a sweet stall. He sees social barriers such as class as the reason why he cannot be more in life, obstacles that prevent him from being able to "make it to the top."
Jimmy rails against the lack of authenticity in human interactions. This can be seen in his attacks on Alison, in lines such as, “Why don't we have a little game? Let's pretend that we're human beings, and that we're actually alive.” Jimmy's abuse of Alison is predicated upon the idea that she does not know what it's like to suffer and experience pure pain. For a large portion of the drama, he sees her as an extension of the false world around him.
These help to explain how Jimmy feels he is misunderstood. He believes that no one can fully "get" him. When he says, "My heart is so full, I feel ill—and she wants peace," Jimmy's frustration is evident. He believes that his own background of having seen his father die has helped to create a perception of realty that no one is ever going to fully understand: "You see, I learnt at an early age what it was to be angry—angry and helpless. And I can never forget it.'' The angry, forlorn condition that Jimmy has carried from his childhood goes very far in defining him in Osborne's drama.