There is a great poem call "If" by Rudyard Kipling. I feel it defines pretty well the traits of a happy person.
Its background is that it was written as a tribute to Jameson after the failed Jameson raid - which was an attempted South African coup
To me, the poem paints an unreachable ideal of being that just doesn't resonate with me at all. It may just be me but in my mind it feels naive.
YouTube link of the recitation for anyone interested: https://youtube.com/watch?v=4EZhc_YZ2fs