Douglas Adams - The Hitchhiker's Guide to the Galaxy

The Hitchhiker's Guide to the Galaxy is a classic and I can totally get the cult status it has for so many years now. I liked it when I first read it and I still like it after listening to the audiobook (read by Christian Ulmen who did a very good job).
Douglas Adams' dialogues are very funny and his ideas are hilarious (who else would think of a depressive robot?). His plot is a bit random, things just happen, and other things happen, and then the next... I know that this doen't change in the other books of the "trilogy" although I can't remember which ones I read and when I stopped reading the series, I didn't finish, that's for sure. There is only so much randomness I could take. Of course it is great if a book gets you to laugh out loud and keeps you smiling. The whole crazyness of it is very enjoyable.
But for me, it lacks the message (which I know wasn't intended) but I like messages in books, even very small ones (like a character finding out things about him- or herself). So fun aside, I miss something in The Hitchhiker's Guide to the Galaxy. But that's just me. Thank you for the fish.