Leon Lederman: Almost all of them seem to happen at three o’clock in the morning, mostly on Thursdays. I don’t know. There is that occasion when you realize that you’re learning something that nobody else knows. It may be you’re alone. It may be you’re with a graduate student. It may be you’re with a colleague. Sometimes it’s very gradual. The data accumulates slowly, and there’s not what we would call the “eureka” instant. But sometimes it does happen that way. I can remember several examples of suddenly realizing that the world is very different from the way the four billion people or so that are on the planet know about it.