Or establishing a habit. I did a month of 'gratitude' challenge which turned into #100happydays since I noticed the benefits and then on and off I'd go back to it again like from the beginning - writing down 5 things I'm grateful for every day. Totally changed my life, you just automatically find more and more things on every step you take to be grateful for and it's amazing how it changes your perspective. You should try as well :)