One difficulty with not "lying" to yourself is complexity. It's often quite demanding to articulate exactly what you know and what you don't. And in the process

One difficulty with not "lying" to yourself is complexity. It's often quite demanding to articulate exactly what you know and what you don't. And in the process of trying, you'll often find that your model of the situation is subtly wrong... but it's hard to say exactly how. To really be in contact with reality, you're a scientist, trying to discern truth. That is, sometimes we lie because it's simpler and less work to articulate. A little similar to advertising hyperbole, lacking nuance. Absolutes are simpler to say, to understand, to reason about. But the article is just talking about active lying: asserting something that you know isn't true (or, that you know you're not sure of).