We have all heard the serenity prayer: God grant me the serenity to accept the things I cannot change, the courage to change the things I can, and the wisdom to know the difference. Being able to differentiate between the things that are up to us and the things that are not up to us is an important step to living a psychologically healthy life.

But our lives can be more complex than that. I’d like to share a model that has helped me navigate and come to peace with the various aspects of my own life.

Life as a “3-Lane” Highway

Here’s the model: Think about your life as a 3-lane highway. Your life is a journey—you’re always moving and heading in a particular direction. Hopefully you are traveling in the direction of your values. Your journey on this highway continues for your entire life—you’re always moving, sometimes faster and sometimes more slowly.

The Fast Lane

The left lane is the fast lane. This is the lane that is moving quickly and smoothly. These are the parts of your life that are going well, without too much effort or difficulty on your part. This lane includes areas that are in your wheelhouse. These are your strengths. In your relationship, the left lane includes areas where you and your partner are on the same page and connect easily.

We might want 100% of our life to be spent in the left lane, but unfortunately this isn’t realistic. Even in healthy, well-adjusted lives and relationships, we can’t stay in the left lane 100% of the time. The best we can hope for is to spend about 1/3 of our lives in the fast lane. When we are in the left lane, the best response is gratitude. Appreciate the times when you are sailing through life easily with the wind at your back. Express gratitude for the times when you are your partner are clicking and connecting easily.

The Middle Lane

The middle lane is the medium lane. You can get yourself moving, but it’s tougher sledding. There is more traffic and congestion than the left lane. These are the parts of your life that you are able to change and adjust, but it requires a lot of time and effort. It can be slow-going. These are areas where you have difficulties and struggles, but you can improve with disciplined effort over time. In your relationship, the middle lane includes the areas where you and your partner can get on the same page, but you have to work at it, negotiate, and compromise.

The middle lane is more difficult and stressful than the left lane, but if we work at it, we can still control our destiny and achieve a good outcome. In healthy, well-adjusted lives and relationships, we usually spend another 1/3 of their lives in the middle lane. When we are in the middle lane, the best response is disciplined effort. We have the power to make a change here, but it is going to take a lot of work. If you truly want to make progress in this area, put a plan together and get down to business.

The Slow Lane

Then there is the right lane. The right lane is the slow lane. Sometimes it seems as if the traffic is completely stopped. These are the parts of our lives that we don’t have the power to change or adjust. These are the things that are outside our control. Maybe it’s something about our parents or our past. Maybe it’s a physical limitation, or a scary diagnosis. This area of our life is not likely to change, even if we try really hard. In our relationships, the right lane includes the things that are outside our control—for example, our partner’s thoughts, feelings, and behaviors.

We don’t like being in the right lane. We don’t like being stuck in traffic. We don’t like coming face-to-face with our limitations. It doesn’t feel very good. But the reality is that each of us has a right lane. Even in healthy, well-adjusted lives and relationships, about 1/3 of our lives are spent in the right lane. When we are in the right lane, the best response is acceptance. If something is truly outside our control, the way forward is acceptance and letting go.

The Wisdom of Switching Lanes

It takes wisdom to correctly identify which lane we should be in at each point of our life. If we misjudge our lanes, and stay in the wrong lane for too long, this can lead to psychological problems. For example, if there is an aspect of our life that we could change or improve with concerted effort (e.g., improve our physical health), but we’re in the right lane, believing that we don’t have any power to change our situation, this is a real problem. We won’t reach our potential. On the other hand, if something is truly outside our control (e.g., the behavior or our partner or spouse), and we’re in the middle lane, trying really hard to control our partner’s behavior, this is a big problem too. Our relationship will suffer because we’re in the wrong lane. Similarly, if we think that 100% of our time should be spent in the left lane, we will be in for a rude awakening when life doesn’t match our expectation.

Action Step: As you go through your day today, if you get frustrated about something in your life, press the pause button and reflect. Ask yourself: “Should this area of my life be in the left lane, middle lane, or right lane?” Then check your response. Does your response match the lane? If not, re-evaluate. Try to come up with a response that more closely matches the lane you should be in.