I used to hate opening my wallet. Every time I pulled out my wallet to pay for something, I’d feel this mild wave of stress wash over me. The source of my stress was the perennial question that stumps us all: Now, which credit card should I use?

You might think that this is totally weird, but admit it – you’ve probably felt it at some point. I know, because I’m a weirdo and I love watching people pay for stuff. I’d see them take out their wallet, open it up, and pause awkwardly as they peruse the twenty credit cards in their humongous wallet.

Why do we do this? Why do we subject ourselves to this tiny piece of stress every day, sometimes multiple times a day? It’s partly because of the credit card companies: They love sending us multiple card offers, because the more cards we own, the ...