I look at having a positive mindset as the ability to remain calm, even when you don't feel strong or confident.
We can practice this and build our capacity to be resilient in several ways. Here are my favorites I practice and share with students:
Have a positive mantra or phrase that you can insert anytime you notice negative thoughts. This concept is not new, but practicing it can get old. It can feel fake or a waste of time to practice this when the scenario is a low key. This is when we CAN practice it, so it's possible in more intense circumstances. For example, in movement based yoga practice, we challenge ourselves with different postures and are coached to breathe calmly. Breathing calmly is one tool to remain calm under stress. Breathing well all the time is good for us too, but that's the yoga teacher in me. Positive thoughts are needed on regular basis to keep the internal reservoir full and trained. When a yoga posture gets difficult, can you coach yourself; I am strong, I can do this! Practicing through pain is not what I am talking about, but exiting a posture the first hint of discomfort is also not what I recommend. Tuning in during yoga helps you notice when you need to positive self talk, and offers a place to practice it.
Let me use a hiking example. This should be an easy image for fellow Southeast Alaskans; a leisurely hike that ends up being longer and wetter than expected. Negative self talk will only be detrimental. There is physical discomfort of being wet and perhaps cold, and mental hurdles of this being more than you agreed to, more than you prepared for. Complaining, blaming, or doubting your abilities, will not help. This is where breathing calmly and positive self-talk will help. If we've never practiced it, the skill won't be effective. Practice when it's easier but needed. Sitting on a beach, on vacation, on honeymoon, is an easy time to say and believe your are awesome and life is grand. Positive talk isn't a fake believe that life is perfect, it's a belief you can remain calm when things around you are turbulent.
Practice in the smaller ripples and let me know how it goes.