Here’s a sobering statistic for you—of all the New Year’s resolutions made, a whopping 88 per cent of them fail miserably. It seems nowadays willpower is in short supply. But it’s not hard to believe; after all, modern life is rife with temptations. Cheap junk food surrounds us, and let’s face it, it tastes awesome. Giant-screen TVs, Internet poker, Twitter—who wants to get up off the couch to go to the gym?

It’s not so much that our collective willpower has never been weaker, it’s that it has never had to work harder. The good news? Knowing just a little bit about how self-discipline works can help us figure out just what we’re doing wrong.

Here’s six reasons why your willpower is failing you, and what you can do about it.