“Is it all my head?” Patients ask me this question all the time. Perception is powerful. What you focus on shapes what you experience.

Here is an example. A recent study found that back and shoulder pain in middle school children was more closely associated with a perception of their backpacks’ weight than with the actual weight of the bag. In other words, if a child thinks her backpack is heavy, the more likely it is she will report pain. Even if it is heavy but she doesn’t think of it as heavy, the less likely she is to experience discomfort.

Examples like these abound. Your perceptions influence what happens. Perceptions can also influence behavior:

Time and again, research has demonstrated the power of an individual’s self-fulfilling prophecies – if you envision yourself tripping as you walk across a stage, you will be more likely to stumble and fall. New evidence suggests that previous studies have underestimated not only the effect of our own negative prophecies, but also the power of others’ false beliefs in promoting negative outcomes.

In one eye-opening experiment, researchers tested whether parents’ negative expectations could predict alcohol consumption in their teenagers over the course of the year. The teens also filled out questionnaires about their drinking habits before and after the experiment. Parents who expected their children to drink reported drinking more. According to one researcher:

Higher expectations for risk-taking and rebelliousness predict higher levels of problem behavior, even controlling for many other predictors of such behavior.

The predictions you make are powerful. I don’t recommend unbridled Pollyanna optimism but a dose of realistic optimism—combining a positive mindset with and understanding of the challenge—can make all the difference.

“Are you really a psychiatrist? Well then, can I ask you a question?” I often find myself in a situation like this in which someone I barely know—a friend of a friend, a stranger on an airplane, a salesperson in a store—shares their story and asks me questions about their lives. They feel trapped—in the wrong job, with the wrong partner, or in the wrong life. Feeling stuck is a recurring theme.

“I am who I am,” they tell me. “Not so fast,” I reply. There are a number of ways to get unstuck and they don’t require radical change. They simply require you to open your mind.

1. Say “yes” to the thing you initially want to say no to:

Instead of retreating into your comfort zone, seize the opportunity to do something new like meeting new friends or working on a new project at the office.

2. Banish the words “I can’t” from your vocabulary:

Micro-defeatist thoughts perpetuate self-imposed fallacies, avoidance reflexes, and the lies we tell ourselves.

3. Turn off the Avoidance Instinct:

It may be our evolutionary heritage to resist unfamiliar situations but it is outdated. Embrace uncertainty. It is a sign you are becoming unstuck.

4. Break your routine:

Routines often go hand in hand with feeling stuck. Do you always go to the same vacation spot? Do you always have brunch at the same place with the same people on Sunday? It’s time for a change.

5. Change your outfit:

Studies show our clothes shape how we feel. It’s one of the reasons people like getting dressed up on Halloween. They get to “be” someone else. Notice how differently you feel when you wear clothes that feel “un-you.” It may help you feel more open-minded, more attractive, and less stuck.

By embracing just one of these strategies, you give yourself the courage and the opportunity to get unstuck in other ways too.

It is so easy to start the day on the wrong foot. You spill coffee all over your white shirt, the dog decided to do his business on the new carpet, the milk you already poured in your cereal is spoiled. You know those days—everything seems to be going wrong.

So, what can you do to turn your bad day around?

Here are six strategies to stop that downward spiral in its tracks:

1. Go take a walk

Studies show spending time outdoors puts things in perspective and stops negative thoughts.

2. Do something for someone else

Buy a coffee for the person behind you in line. Send an email to an old friend.

3. Get specific

Figure out what exactly is bugging you. Once you pinpoint the problem it is easier to deal with it.

4. Flip it around

Take five minutes to think about three things that are going well in your life. It can’t all be bad.

5. Set yourself up for small wins

Write down one thing you know you can accomplish today and do it.

6. Mix it up

Instead of stewing at your desk and feeling sorry for yourself, do something different. Bust out of your routine. The moment you take yourself off autopilot, you ground yourself in the present. This helps you stop ruminating about all the bad things that have happened.

Even if you don’t feel like doing any of the above and prefer to wallow in your bad mood, it’s worth doing it to spare those around you. Bad moods are contagious. The good news is good moods are contagious too.