David McRaney spends a lot of time thinking about all the ways thinking doesn’t work. He catalogues delusions, fallacies of thinking, and the psychological short-circuits that cause procrastination, groupthink, and poor decisions. But McRaney swears his index of common mental shortcomings actually inspires him–and could inspire you to know thy working self.

You Are Not So Smart, McRaney’s blog and forthcoming book, is intentionally labeled as a “Celebration of Self-Delusion.” Sure, topics like the bystander effect, showing how bigger crowds encourage less help for people in trouble, and the backfire effect, where people learn to reject science when it questions their beliefs, are likely to get under anyone’s skin after some reflection. But McRaney says that understanding our mental malfuctions should inspire us.

“(It’s) an appeal to be more humble and recognize we can’t always overcome these things, so we should factor them into our lives, our business practices, our politics,” McRaney wrote in an email exchange. “If we know we are all equally susceptible to certain fallacies, biases, heuristics, prejudices, manipulations–we can use that knowledge to appeal to our better angels.”

Here are a few of the self-delusions McRaney writes about that are most apt to throw you off during those 40 hours you’re paid to think straight and make decisions.

The Sunk Cost Fallacy

You’d like to believe that you can evaluate the future worth of a project, an investment, or just a laptop with the stoic gaze of a Wall Street lifer. But you tend to favor those things you’ve already “invested” in, because otherwise–horror of horrors–you’d have made a mistake in your past.

That’s the sunk cost fallacy. Another short version: The pain of losing something is twice as strong as the joy in gaining the same exact thing. McRaney wrote that this single understanding has made the biggest change in his life. “There are a lot of applications, like ejecting from a career path, a degree, or a relationship instead of staying the course, just because you’ve already invested a lot of time and effort into it. It’s a silly thing we all do, and I used to fall prey to that one every day.”