Hm. I have a good place to live, a great family, and so forth, yet I'm not quite there. I don't have a lot to complain about - I make a decent, if not phenomenal wage, at a stable job with good benefits with work that I actually enjoy. I have a great marriage to the best woman in the world and a troupe of 6 healthy children who are all pretty great.
My main issue right now is an existential/social issue where the authorities I trusted growing up (parents and church mostly) all said that it was better to live a life of virtue even at the expense of finances, social status, or anything else. After a decade or so of actually doing that, it turns out that they all pretty much only care about how much money I make (that I would theoretically give to them).
...And I could have optimized for money, if I had known that was the only thing they actually cared about. It's a bit late now, though. Unfortunately I am just enough autistic to take people at their word and not catch the secret subtext. So I've lived the life of virtue as well as could be done, and they are all incensed that I haven't done all that and also become a multimillionaire (and giving the money to them). As if the very wealthy in America have any integrity at all.
I also have some long term personal issues that I have been unable to make any progress on.
The best advice I've seen is that happiness is a state of mind. I won't endorse it though, until I figure it out for myself. The world is full of advice that sounds good but doesn't work. Most parenting advice is like that. I won't give advice that I haven't personally verified though. I've known people that claim to be happy when they're staring down the barrel of a gun every night.