I think the theme of this book is that not everything is as it seems. One example of this theme is when Arthur hears about the white mice controlling the Earth and humans when he thought that humans controlled white mice. "Ah no," he said "I see the source of misunderstanding now. No, look, you see what happened was that we used to do expiriments on them" (147). Another example is when Arthur had met Zaphod when he gate-crashed a party and took home a girl Arthur had been hitting on, and in real life he actually had three arms and two heads. "Be only had the two arms and the one head, but..." (98). My last example is when the Vogon destructor fleet comes and Ford knows about it because he is an alien. "The contacts of Ford Prefect's satchel were quite interesting in fact and would have made any Earth physicist's eyes pop out of his head, which is why he always concealed them by keeping a couple dogeared scripts for plays he pretended he was auditioning for in the top" (23). I think that the theme of this book is that not everything is as it seems.
I would definitely recommend this book to other people. It is very absurd, so if you want to laugh you will love it. The author, Douglas Adams, was an atheist and it does show through in his writing, so if you're very religious you might not enjoy it. It is extremely funny and usually completely random and is garentied to make you laugh out loud. Overall it is inspired, funny, and over much too soon. I would definitely recommend this book to others.