The actual results starkly diverged from participants’ explanations. Yes, they were somewhat more likely to drink coffee when tired – as would be expected – but it was found that habit was an equally strong influence. People overestimated the role of tiredness and underestimated the role of habit. Habits, it seems, aren’t considered much of an explanation.

The gap between the actual and perceived role of habit in our lives matters. And this gap is key to understanding why people often struggle to change repeated behaviors. If you believe that you drink coffee because you are tired, then you might try to reduce coffee drinking by going to bed early. But ultimately you’d be barking up the wrong tree – your habit would still be there in the morning.

The reason that habits can be so difficult to overcome is that they are not fully under our control. Of course, most of us can control a single instance of a habit, such as by refusing a cup of coffee this time or taking the time to offer directions to a lost tourist. We exert willpower and just push through. But consistently reining in a habit is fiendishly difficult.

We make a similar error when we try to control unwanted habits and form new, desirable ones. Most of us can achieve this in the short run – think about your enthusiasm when starting a new diet or workout regimen. But we inevitably get distracted, tired or just plain busy. When that happens, your old habit is still there to guide your behavior, and you end up back where you started. And if you fail to recognize the role of habit, then you’ll keep overlooking better strategies that effectively target habits.

We don’t recognize the benefits of our good habits. One study found that on days when people strongly intended to exercise, those with weak and strong exercise habits got similar amounts of physical activity. On days when intentions were weaker, however, those with strong habits were more active. Thus, strong habits keep behavior on track even as intentions ebb and flow.

Research shows that, surprisingly, people who are more successful at achieving long-term goals exert – if anything – less willpower in their day-to-day lives. This makes sense: Over time, willpower fades and habits prevail.

Changing habits begins with the environments that support them. Research shows that leveraging the cues that trigger habits in the first place can be incredibly effective. For example, reducing the visibility of cigarette packs in stores has curbed cigarette purchases.

Making it difficult to act on undesirable habits and easy to act on desirable ones. For example, one study found that recycling increased after recycle bins were placed right next to trash cans – which people were already using – versus just 12 feet away.

Effectively changing behavior starts with recognizing that a great deal of behavior is habitual. Habits keep us repeating unwanted behaviors but also desirable ones.

“We are what we repeatedly do. Excellence, then, is not an act, but a habit.”

-Will Durant

“Chains of habit are too light to be felt until they are too heavy to be broken.”

-Samuel Johnson

“Motivation is what gets you started. Habit is what keeps you going.”

-Jim Ryun