Well, I mean it is, in general of course; but for me the art of being happy lies in finding the opportunity to be of service in every situation -- to approach every person, place or thing with an attitude of "What can I bring to this, what can I contribute, what can I give?" as opposed to "What am I going to get out of this?" and the ever popular "Where's mine?"*
That, and gratitude.
For me that's where the art of being happy lies.
*And it strikes me, as I write the above, that the "take" attitude is one sourced ultimately in Fear, while the "giving" attitude springs from Love in some form -- or at least a willingness to act in a loving way -- and doesn't that also speak to a Universal Truth of sorts?