This is absolutely my favourite quote from The Guide:
"I'm a scientist and I know what constitutes proof. But the reason I call myself by my childhood name is to remind myself that a scientist must also be absolutely like a child. If he sees a thing, he must say that he sees it, whether it was what he though he was going to see or not. See first, think later, then test. But always see first. Otherwise you will only see what you were expecting. Most scientists forget that. ... So the other reason I call myself Wonko The Sane is so that people will think I'm a fool. That allows me to say what I see when I see it. You can't possibly be a scientist if you mind people thinking you're a fool."
-- Wonko The Sane