In-the-Moment Happiness is related to expectations vs reality.
There’s a physiological ceiling to happiness. Happiness has to do with expectations. If you expect food and freedom, you aren’t really made happy by it. Your expectations grow with your progress.
This is also why it’s so frustrating when your Effort vs Progress Monitor says you’re not making much progress as you should for the effort you’ve put in. You should ask yourself “What is this Situation Asking of Me?”
This is also partially why you should Compare Yourself to Your Average instead of your best. You won’t (probably) do your very best today, but you might do better than your average.
This also is one reason why financial advice is to avoid Lifestyle Creep, as it keeps your money low without really doing anything for your happiness. The Diderot Effect also comes to mind.