I propose you to try the following exercise: "My three favorite moments of the day". The impact on yourself is tremendous!
At the end of the day, before going to sleep, write in a notebook (or on your Facebook profile as the current challenge requests you to do) your three favorite moments of the day.
Thereby you will end your day on a positive note.
Writing makes your idea more concrete. They are not "floating in the air" anymore.
If you collect all your favorite moments in a notebook, it is easier to read them in a row.
If you got nominated on Facebook, you need to write 5 days in a row your three favorite moments of the day on your profile.
Personally, I write my favorite moments in a notebook already every night since months. I notice my mood and mental state changed. Because I am focused on positive moments and experiences, I forget little by little the less good ones. I am more positive, more optimistic and happier.
Try this exercise and tell in the comment section how it affected you!