Basically Frank's life has not turned out as he wanted or expected. His marriage failed, he did not gain success as a poet and he is fighting with Julia, the woman he lives with.(He describes his own poetry near the end of the play as "worthless, talentless shit.") In his 50's now, his chance to be a shining literary light has passed and he has turned to alcohol to cope with his world. There is more than a suggestion in the play that he finds the conservative university to be smothering him, but he despises himself and his lack of motivation/energy. His existence is boring and fairly meaningless-that's why he sees Rita's views as different and interesting. (These are just my ideas-there are probably more! I think his age is a big factor. He thinks he is past it and a failure.) Cheers.
