For:
1)constantly think about happiness
2)for single people:
Have congenial friends
Have a satisfying work
Love life
Recognition by others for what they are doing
3)happy childhood
4)how you regard your circumstances
Against
1) do not think about it so often,
2)for married people:
Happiness from family life
Personal growth and development
3)people who came through bad early and teenage years are happy as adults
4)what the circumstances are