I apologize in advance for sniffing my own ass, but this is what term happiness always meant to me, I knew from a very young age the difference between happiness and pleasure, and I learned the hard way that they weren't always correlated... there were some moments I was in pure tears but I felt that greater sense of being and purity because I knew I had done the right thing, or it felt "real" or came at a time when i was just generally well calibrated. And of course the inverse is true, if you're in a bad mindset pleasure feels like coal. I'm not sure why this came to me so early, I'll chalk it up to being raised right and having a really good childhood with great parents who guided me properly.
I was in 12th grade before I realized that a lot of people don't care about that and only care about surface level pleasures. It was really disturbing the first time I had a conversation with a close friend and realized this about him. But it made a lot of things make sense.