And serene, achieving serenity, is something to wish for others and strive for oneself. I completely agree with you on happy. Its an emotion that comes and goes as it should. Constant happiness is mania. Just like sadness is an emotion that comes and goes as it should. If it doesn't, that's depression. Early in my Medium experience, about 4 years ago, I wrote:

"I seek contentment, which is not settling but a hopefully high-altitude baseline, coming from within and connection to without. It doesn’t stem from the acquisition of attachments but awareness of connection to the world and the universe as a living, breathing, and heart-beating organism and from alignment of mind and soul and discerning my why — my drive — from discovering who I am at my core."