I am not happy all the time,contended most of the time.
It has taken me many years, OK, decades to learn to switch on and off my state of mind.
Example,the share market has not been kind to me of late, but am not unhappy. I have decided to do things that make me content and happy regardless of share market. That is the choice that I have.
It is a mental switch that one must master.
As in my signature,
"It's not what happens to you, it's how you handle it, that's important."