Why is Jimmy Porter terribly angry in Act 1?

Jimmy is angered a few times.... first, he throws his paper down in disgust. He complains that all the book reviews sound the same and that the papers provide no intellectual stimulation. He asks Cliff antagonistically if the papers make him feel ignorant. He calls Cliff “a peasant.” The audience comes to understand that Cliff has not received the same education that Jimmy has received. Jimmy then turns his antagonism towards Alison who is only half listening to his rantings. Cliff tries to deflect some of Jimmy’s anger away from her, but Jimmy keeps on with his ranting. Jimmy obviously feels that Alison is not as brilliant as she and others think she is. Jimmy then becomes upset that nobody is listening to him when he speaks and he steals the newspaper from Cliff.

Later, the concert that Jimmy wants to listen to comes on the radio and Alison finishes ironing Cliff’s pants. Alison keeps ironing and Jimmy complains that he can’t hear the music because of the noise. He angrily turns off the radio and Alison chides him for acting like a child. He begins to yell about how loud women are and describes her clumsiness by telling her she is like “a dirty old Arab, sticking his fingers into some mess of lamb fat and gristle.” Church bells start ringing outside and this noise upsets Jimmy even more. Cliff, trying to improve the mood, pretends to dance with Jimmy to the bells and grips him in a vice while Jimmy protests.