HALFWAY THROUGH J.K. Rowling's latest book, Harry Potter and the Deathly Hallows, Harry and his two friends are on the run. They're trying to find the evil lord's "horcruxes," which are objects containing part of his soul. They need to destroy the horcruxes. They've found one but haven't figured out how to destroy it. They don't know where to begin to look for the others. Things aren't looking too good for our heroes.

Then Harry's best friend (Ron) gets mad and leaves. To Harry, this is a setback. He needs Ron to help him accomplish his goal. And what does a setback always do? It makes you feel demoralized. And when you feel demoralized, your mind starts making mistakes, and those mistakes make you even more demoralized. Here's a passage from the book that perfectly illustrates it. This is what was going through Harry's mind:

He could not hide it from himself: Ron had been right. Dumbledore had left him with virtually nothing. They had discovered one Horcrux, but they had no means of destroying it: The others were as unattainable as they had ever been. Hopelessness threatened to engulf him. He was staggered now to think of his own presumption in accepting his friends' offers to accompany him on this meandering, pointless journey. He knew nothing, he had no ideas, and he was constantly, painfully on the alert for any indication that Hermione too was about to tell him that she had had enough, that she was leaving.

In his depression, Harry exaggerates: He had no ideas, he knew nothing. This wasn't true. But can you see how feeling demoralized makes those kinds of thoughts easier to think? And can you see how thinking those thoughts would make him feel even more discouraged?

Hopelessness "threatened to engulf him," but this was false hopelessness. There was still plenty he could do. Thinking of his situation as hopeless took the fight out of him, as it would for anyone. He desperately needed to argue with his own thoughts to straighten out his thinking.

Okay, let's look at one more thought-mistake Harry is making and then we'll leave the poor kid alone. He calls their mission a "meandering, pointless journey." This is the mistake of harmful judging. In fact, their journey is vitally important and he is the only one who has a chance of succeeding with it. Yes, he may fail. But if he succeeds, he may save thousands of lives, maybe millions. But harmful judging doesn't help. It only makes him feel demoralized and unmotivated.

His depression also influences his perception, as it does for you and me. He begins to feel hypersensitive about how Hermione feels, maybe misinterpreting some of the expressions on her face and things she says.

You know what that's like, don't you? Everyone has been in a bad mood and interpreted a friend's innocent comment as something malicious.

And of course, misinterpretations can easily make negative predictions come true. Harry might accuse Hermione of thinking something she's not really thinking, which might make her angry. And now she is thinking what he accused her of thinking.

The point of all this is to let you see it from the outside. I thought J.K. Rowling did a great job of conveying the feeling of demoralization and the kind of thought-mistakes that accompany and intensify that feeling.

And my other purpose is for you to realize you should waste no time when you feel disheartened.

Don't let yourself spin down into a dive. Run — don't walk — to the nearest paper and pen and start using the antivirus for your mind. Undemoralize yourself as soon as possible. You don't want any of those thought-mistakes to solidify into beliefs — the kind of beliefs that might hold you back from goals you want to reach.

Clean out your mind and your motivation will return. The antivirus for your mind works like magic to get you back on your feet and striving toward your goal with determination and vigor.