You have a choice every day when you wake up. It isn't an easy choice, but it is a choice. You can wake up and decide to be in a good mood, a neutral mood, or a bad mood every day.
You may not be able to keep that mood choice throughout the day, depending on your initial choice, and what happens that you have no control over. The only thing you have control over is yourself and your own actions.
By internalizing this attitude to the point that one always wakes up in a good mood, it makes it much easier to suffer through the hard days, and infinitely easier to enjoy the good days.
The biggest challenge I have currently is not despairing because no one is effectively fighting fascist authoritarianism.