6. Exercise
It’s science: exercise makes you feel good. Not only does it build your muscles and help maintain weight, a short workout can release endorphins and increase serotonin and dopamine levels, making you feel happy. Exercise reduces the effects of stress—a major component of your brain at the end of the year. It also helps you improve your memory, so you won’t have to embarrass yourself at the office Christmas party when you forget your boss’s spouse’s name.