What is the Happy Post Project? from Steve Vollbach on Vimeo.
Nice, right? You may never look at a post-it again without thinking of something that makes you happy. ;)
Also, in standard DH fashion, something weird that makes Mario happy is playing the air guitar. (Fun fact, he was the champion air guitar player in school.) And his favorite happiness quote is:
Happiness is when what you do, what you think, and what you say are in harmony.
-Gandhi