yeah, it resembles the "happiness is a choice" motto used and repeated by many. I would say that it isn't always the case

Agreed. Sometimes, it is exceedingly difficult to step outside your immediate emotional state to make rational decisions.

As a retired EMT, I have spent a lot of time helping people in extreme situations to elevate their consciousness above the immediate flood of input. I was not always successful, but the capability of the human brain to filter input is rather astounding.

It is almost always the case, at least in some point of everyone's life. In a lifetime, every human being can find happiness and joy in life.