Here's a quick list to inspire a new definition of happiness in our daily lives. I suggest you write your own customized one and make a poster out of it for your room. You can look at it the instant you feel down to brighten your day.
1. Sing The Duck Song

2. A good pun is its own reword

3. Make random laughing sounds

4. Watch favorite childhood cartoon

5. Shout Allahu Akbar!

6. Make silly faces in a mirror

7. Leave a questionable message on a friend's voicemail

8. Tell a kid a story that has no beginning middle or end.

9. Bubble wrap.

10. Sip tea

11. Watch an old home video

12. Change your accent

13. Dance when no one's watching

14. Surprise a friend

15. Wear white or yellow

16. Do the Macarena

17. Smile for no reason

18. The word "sassafras".

19. Cat videos

20. When in doubt, one word; food.

None of these worked for you? Maybe it's time to get some time off.