I think the current consensus is that in fact having more money does make you happier.[1] As for richer, I can look at how I've lived in the past and observe that I've been pretty effective at being frugal and not spending money just because I have it. Of course it's possible that a sudden cash infusion 10 years ago would have broken all those good habits, but I don't see any obvious reason to believe it.
[1] See e.g. this (though I'd be a bit cautious given where it's being reported) and the underlying research.
[EDITED to fix a formatting glitch.]
As I said, this is the standard answer I get, albeit a little bit more sophisticated than the average.
Unless you're already rich and still having good saving habits, I see a very obvious reason why you should have broken those habits: you suddenly don't need to save anymore. All the motivational structure you have in place to save suddenly lose meaning.
Anyway, I don't trust myself that much in the long run.
r/Fitness does a weekly "Moronic Monday", a judgment-free thread where people can ask questions that they would ordinarily feel embarrassed for not knowing the answer to. I thought this seemed like a useful thing to have here - after all, the concepts discussed on LessWrong are probably at least a little harder to grasp than those of weightlifting. Plus, I have a few stupid questions of my own, so it doesn't seem unreasonable that other people might as well.