It’s probably true that in almost any situation there is something negative, difficult, disheartening or unfortunate that you could focus on.
And focusing on those things will rarely make you feel good so why not instead just focus on the good bits. Focus on the bits that bring you joy, make you happy and make you excited about life.
It’s not that you should ignore things that need sorting out or just put your head in the clouds. However, sometimes having the kind of perspective where you focus on the good bits allows you to see the not so good bits with a level of clarity, this then allows you to move forward and progress.