Happiness is fleeting. Contentment/being at peace is a much better goal.
Sometimes things will happen to make you feel unhappy. The person who is hysterically happy at a funeral probably needs to see a doctor.
But being at peace with your lot in life is much better than the alternative. There's a difference between the person who MUST have more A,B,C,D to be content, and the person who is just content with what they have and they might have preferences for A,B,C,D and they may work towards those things, but they don't HAVE to have them to be content.
In any case I find it useful to remind myself from time to time, *you are currently in a room *in a suburb *in a city *in a state *in a country *on a planet * in a solar system *in a universe... and you are a tiny tiny little speck of existence, on a planet that will one day be wiped out, in a solar system that will one day collide with another solar system and be destroyed, and everything you do, everything you say, everything you think will come to nothing. So why stress? Just enjoy your speck of existence as best you can.
I think life is a bit better after we get over ourselves.