Warning. You're going to need your towel.

Thirty years on from its creation, The Hitchhiker's Guide to the Galaxy is still among the best known science fiction writing in the English language. Look at the ratings – still there, way up among the Amazon bestsellers in both SF and comedy lists, and right there alongside upstart Booker Prizewinners and other ephemeral froth in the literary rankings. Yet if Douglas Adams was destined to become the 20th century's greatest popular SF writer, it wasn't clear to him in the early days. He wasn't even sure if he was keen on the genre. When asked if he liked science fiction, he'd give one of his typically thoughtful answers:

"Well, yes and no. I like the aspects of it which turn the telescope round, by letting you stand so far outside things and see them from a totally different perspective. That's what I try to do in Hitchhiker's, and that's what I think the best science fiction does. Science fiction that's just about people wandering around in space ships shooting each other with ray guns is very dull. I like it when it enables you to do fairly radical reinterpretations of human experience, just to show all the different interpretations that can be put on apparently fairly simple and commonplace events. That I find fun."

Douglas Adams: The First and Last Tapes. (darkmatter.com)