This is a great passage from the book Future Babble:
Be articulate, enthusiastic, and authoritative. Be likable. See things through a single analytical lens and craft an explanatory story that is simple, clear, conclusive, and compelling. Do not doubt yourself. Do not acknowledge mistakes. And never, ever say, “I don’t know.”
People unsure about the future want to hear from confident experts who tell a good story, and Paul Ehrlich was among the very best. The fact that his predictions were mostly wrong didn’t change that in the slightest.