Happiness and its relative opposite, sadness, are the same dream. Both are temporary experiences we develop varying degrees of attachment or aversion to.
They are the fundamental ingredients, like garlic and ginger, to life's drama. Just about every story that has ever been created in the long history of storytelling, has been about the resolution of sadness or suffering in order to achieve happiness. We relate to this story on a primal, visceral level.
The wise, however, recognise periods of sadness as opportunities to listen, go within, and learn. And they are skeptical of periods of happiness, as the positive feelings, like a sugar rush, distract attention away from more truthful levels of being. To them, neither experience is preferred nor sought. Both are welcomed when they come and let go of when they are ready to leave.
The even more wise recognise and gravitate toward a state beyond happiness and sadness, where the two poles merge and cancel one another out like an equality statement.
Joy is. It is your natural state of being. Underneath all the pain, suffering, and toxic psychological/emotional layers, it is there waiting to be released, like a dammed up river.
Joy has no beginning and no end. It is not dependent on any external circumstance to exist but, you need to be ready and thoroughly prepared for the overwhelming and awesome experience of it.
Everybody would prefer an unbroken experience of joy to temporary periods of happiness any day of the week. However, very few are willing to make the sacrifices to have it.
First and foremost, experiencing unbroken joy requires letting go of life's drama for good (aka "sobering up"), which has real and profoundly challenging consequences, especially socially.
Then, it is a matter of constantly purifying and refining your character so that you become clear enough for the joy to flow through you, unimpeded. This means regularly updating your values, everyday habits, and behaviour until they are totally and perfectly aligned with the truth—and unable to be changed any further.
Conceptually, it's simple. However, consider how hard it is for people to quit smoking, then multiply that one habit times ten thousand and you have an idea of the difficulty of this work.
What's the alternative though? Staying stuck in the drama of temporary periods of happiness and sadness.