I actually couldn't finish this book, because I just found the author to be so arrogant.
The book starts as a generalised overview of communism interspersed with communist jokes and occasional passages oozing with sentimentality about a former East German girlfriend. While these sentimental bits weren't particularly bad to start with, even slightly touching, by the end (I mean by the time I stopped reading!) I was rooting for it to end in abject misery as I absolutely couldn't stand the guy. After a while the history of communism ends and the framework for the narrative becomes his inquiry into communist jokes, mostly trying to force them into a theoretical framework he appeared to arrive at very early on. What finally stopped me reading was the author's (not at all concealed) contempt for everyone he interviewed. While Lewis managed to secure some incredible interviews with very central and informative individuals, he has no respect for any of these people, as he makes abundantly clear in his descriptions of his various interviewees as naive idealists, drunks, and delusional geriatrics.
Great subject, I recommend people read about it, but buy a different book.