“Protect me from knowing what I don't need to know. Protect me from even knowing that there are things to know that I don't know. Protect me from knowing that I decided not to know about the things that I decided not to know about. Amen.Lord, lord, lord. Protect me from the consequences of the above prayer.”

“You know," said Arthur, "it's at times like this, when I'm trapped in a Vogon airlock with a man from Betelgeuse, and about to die of asphyxiation in deep space that I really wish I'd listened to what my mother told me when I was young.""Why, what did she tell you?""I don't know, I didn't listen.”

“I don't know what this great thing I'm meant to be doing is, and it looks to me as if I was supposed not to know. And I resent that, right? "The old me knew. The old me cared. Fine, so far so good. Except that the old me cared so much that he actually got inside his own brain--my own brain--and locked off the bits that knew and cared, because if I knew and cared I wouldn't be able to do it. [...] "But this former self of mine killed himself off, didn't he, by changing my brain? Okay, that was his choice. This new me has its own choices to make, and by a strange coincidence those choices involve not knowing and not caring about this big number, whatever it is. That's what he wanted, that's what he got. "Except this old self of mine tired to leave himself in control, leaving orders for me in the bit of my brain he locked off. Well, I don't want to know, and I don't want to hear them. That's my choice. I'm not going to be anybody's puppet, particularly not my own. [...] "The old me is dead! [...] Killed himself! The dead shouldn't hang about trying t0 interfere with the living.”

“Ok," he said, "I don't like to disturb you at what I know must be a difficult and distressing time for you, but I need to know first of all if you actually realize that this is a difficult and distressing time for you.”

“You know what a learning experience is? A learning experience is one of those things that says, "You know that thing you just did? Don't do that.”

“Sorry, did I say something wrong?" said Marvin, dragging himself on regardless. "Pardon me for breathing, which I never do anyway so I don't know why I bother to say it, oh God I'm so depressed. Here's another one of those self-satisfied doors. Life! Don't talk to me about life.”

“I refuse to answer that question on the grounds that I don't know the answer”