It’s because we love it. We love grinding.

We cannot get enough of it.

Why? Because there’s something enormously comforting about grinding. It offers a completely straightforward relationship between work and reward. When you log into WoW, you know beyond a shadow of a doubt that if you just plant your ass in that chair for long enough, you’ll level up. It doesn’t require skill. It just requires putting in the time. Play 10 hours, you’ll do better; play 50, you’ll do better yet; and yet more so with 500 hours.

The thing is, almost no arenas of human endeavor work like this. Many are precisely the opposite, in fact. When you go to your job at the office, there’s little or no linkage between effort and achievement: You slave like a madman all year long, only to watch the glad-handing frat guy hired two months ago get promoted above you. And if you’re a really serious nerd, the logic that governs interpersonal relationships — marriage, kids, your parents — is even more abstruse: Things can actually get worse the more time and effort you put into them.

But grinding? Grinding always works. Always. You get a gold star just for showing up. This is a quietly joyful experience. It feeds our souls, as well as our sense of justice and fair play. We grind because we can’t believe what a totally awesome deal we’re getting handed here, often the first time in our entire suck-ass put-upon lives.