Often we know what needs to be done to improve our lives, but we just aren’t doing it. Whether it is exercising more, drinking less, working less or harder, getting more sleep or healthier eating, we know what would help us to feel better, but we don’t act on it because the habits that must be changed are so ingrained in our minds and our daily routines. In fact, Americans cite lack of willpower as the number one reason why they don’t manage their stress better.

In spite of countless articles all year long about how to keep our resolutions, our understanding of willpower is still limited. We seek the holy grail of willpower that will enable us to do the things we know we should do.

Part of why we fail is that we confuse willpower with desire.

Willpower and desire are opposites. If we wanted to do something, it wouldn’t require willpower; it would be easy. The things that we ought to do but aren’t doing are, by definition, difficult or we would be doing them already.

Willpower is a decision, not a feeling. If we wait until we feel like doing this difficult thing, it usually won’t happen. Ask alcoholics in recovery: they commit to not drinking on a day-to-day basis, all the while facing intense cravings and urges to drink.

Willpower is an ongoing commitment to ourselves. It is a decision made over and over and over again until it becomes the new habit.

We struggle to do new things because our current behavior patterns are wired in our brains. The beauty of our biological design is that the brain forms neural networks to automate our behaviors so that we can do things effortlessly. This becomes a problem, however, when the effortless pattern is a dysfunctional one and the healthy behavior hasn’t been wired in yet.

To develop a new habit, we must stretch ourselves and literally change our brains. The old automated behavior is easy; it’s what we want to do because it is our habit and has a strong neural network to grease the skids. The new behavior has a fledgling neural network that easily loses out to the dominant mode.

When we are in our usual mode, it’s like we are speeding along on a superhighway. Our new resolution is a field of tall grasses with no path at all. We have to whack away with our machete to clear a trail, put down gravel and eventually pave the road to make easier to follow. Eventually the superhighway will crumble and our new road will become the thoroughfare. But as you can see, it’s hard work, and it takes time.

Though this explanation might be discouraging, it is important for you to know what is needed and why developing new habits is so hard. Our biology is in our way when we are trying to do something new. But the key to doing it anyway is learning the difference between wanting to do something, and becoming willing to do it, even though we don’t feel like it.

That’s what willpower is: becoming determined to do something even though you don’t want to do it.

Psychologists Marsha Linehan and Steve Hayes have written compellingly about willingness. Their therapeutic approaches have helped those who suffer most deeply to stop waiting until they feel ready to change. Instead they have clarified that our feelings, thoughts and urges need not direct our behavior, especially when they point us toward self-destruction.

To make a healthy choice in the face of self-destructive urges, we must add new thoughts. For example, to build the new practice of eating well, you might develop a vivid reminder of the benefits you will gain with better nourishment. However, it is important to realize that these new thoughts will likely coexist with the magnetic attraction of eating poorly. The old thoughts, feelings and urges won’t go away until the new neural network in your brain is the dominant mode.

We might get discouraged because our unhealthy thoughts, feelings and urges keep showing up when we are trying to practice new, healthy behaviors. But when we understand how the brain works, we see that this is normal and to be expected. We know that our brains are working against us for now. But once we establish the new neural network, our brains will work for us. It just takes time and hard work to get the new path constructed.

As they say, “Just Do It!” and the new habit will become easier over time.