A few days ago I ordered 61 books, most of which you’ve probably never heard of. I didn’t even flinch when Amazon stopped incrementing my shopping cart at 50 items. And the final tally of $1,201.40 represents only a small percentage of the money I routinely spend on books in any given year.

You might ask why I spend so much money on books when I could just borrow them from a library. First, my local library is unlikely to have all the books I want to read (more on that later). Second, when I’m reading a good book, I want to read it actively. I want to write in the margins. I want to make notes. I want to make it my own. If you get a library book, you can’t do that.

I buy every book I want, with few exceptions. As someone who reads over 100 books a year and has an anti-library with thousands of titles that I haven’t read, I can assure you my habit gets expensive. Yet this doesn’t bother me at all.

Books contain a vast amount of knowledge, and knowing what most other people don’t know is how I make a living. While books can be expensive, ignorance is costlier.

I also go out of my way to read books that are flying below the radar. As Haruki Murakami put it, if you read what everyone else is reading, you’re going to think what everyone else thinks.

But in our competitive world, being average isn’t an option. You need knowledge and ideas that other people don’t have. You need to make yourself into a scarce resource.

In his book Average is Over, economist Tyler Cowen talks about what is scarce and what is not in today’s global economy. “Intellectual property,” he writes, “or good ideas about what should be produced” is scarce and valuable.

So if you’re trying to get ahead, skip the bestseller displays at the front of the bookstore and head to the stacks at the back. Bestselling books, almost by definition, rarely help give you an edge. Sure, they might help you sound smart at a cocktail party, but that’s only because everyone else is reading them and they want to seem smart, or worse, “current.”

Personally, I spend a lot of time with the dead. That’s why my cart was full of books that are out of print. Books like Unended Quest, Inside the Record Business, and Roman Honor: Fire in the Bones. Interestingly, this habit typically makes the books either ridiculously cheap — $0.01 plus shipping — or ridiculously expensive.

The most expensive book I ever bought was Henry Miller on Turning Eighty, which was over $800 but resulted in learning a lot about why life is the best teacher and the complicated relationship between friendship and getting older.

I might not read every book I buy. I might never even crack the spine on a few of them. They might turn out to be a waste of money. But I keep spending money on them because I know the right book may change my life.

Reading is a long-term investment I make in myself. I can’t afford not to.

This post is adapted from a piece that originally appeared on Medium. Subscribe to The Brain Food Newsletter. You can follow Shane on Twitter and Facebook, and read more of his work at Farnam Street.