They say “ignorance is bliss,” but in my experience there seems to be a pretty strong correlation between how happy someone is and how seriously they can – and do – think about their life and the sources of that happiness.
There is a lot of natural happiness in the world, but there’s a lot of other natural resources too – that doesn’t mean it doesn’t take labor to convert the natural resource into something usable by humans. Children might be one of the purest and most bountiful sources of happiness in existence, but if you just have a bunch of kids with zero effort or thought put into preparing for and raising them, you’re not likely to be happier on net than if you had none at all.
Happiness, joy, contentment – these things take work. And to be effective, I think that work has to be pretty regularly examined and re-examined for flaws or potential improvements.
The challenge is in overthinking. Happiness isn’t binary. You don’t cross a threshold and wake up content one day. These things happen by inches and fractions of inches. So no matter what you do, you could always, perhaps, be a little more happy. It is up to each individual to decide when additional effort towards that goal won’t actually be a marginal improvement anymore. Call it the “Pursuit of Pareto-Optimal Happiness.” You won’t get it perfect. But I think time spent in contemplation is, on net, an asset.