I'm not sure I've ever known and am not certain I will. I can be happy in a moment, but that goes away. Meds help me shrug it off, and I don't tend to dwell on existential shit like this for long, but like...I dunno that I was cut out for this world, yo.
Also this isn't a cry for help and im not particularly sad or upset right now, I was just walking one of the pups and thought to myself "if I can't be happy I'm gonna make sure these fuckers are."
Happiness is a reductionist concept in a reductionist culture we're embedded in. I'd even say it's a mental trap. We boil everything down to a single simplified axis of "good" or "bad" because that is the mindset this society prefers, and most often, it takes the form of a mirage, an aspiration, a simplified memory. I don't think "happiness" is useful or adaptive at all.
You can break it down into joy, anticipation, pleasure, contentment, satisfaction, significance, optimism, inspiration, and many other things. Happiness is a blanket concept that covers all of these, but you're "supposed" to be having it... like all at once? That makes no sense. You'll have some at some times and some at others, and if you try to condense it all to a scale, you're always going to be deficient because there will be some of them missing at any given time. Like other blanket concepts (intelligence, athleticism, maturity, leadership), it's more accurate and helpful to keep the components broken apart instead of all rolled into one.
If it means anything to you, for much of August of last year I was remarkably affectively positive.