I would look into very basic texts (doesn't even have to be a full book) on what a proof is and how proofs work, e.g.:
http://math.berkeley.edu/~hutching/teach/proofs.pdf
I would also learn enough causal inference stuff to recognize when the {press|people on the internet} are talking out of their asses about an empirical result. Usually this is of the form [policy prescription based on observational data], e.g. "scientists find wine is correlated with life expectancy, so drink wine to live longer!" People, even otherwise very smart people, get this wrong surprisingly often.
But I would say that!
If you know a bit of math that comes up often, you can use it as a sanity check for how careful people are about things you may not know about. That is, if they screw up what you know, that means they probably screw up other stuff.
I want to have access to outlook-changing insights.
"Insight porn" is not how real intellectual growth happens, at least in my experience. New insight feels nice, but lasting behavioral change isn't sudden. Learning new stuff generally outpaces a consistent ability to act on that knowledge in our society.
With regards to insight porn, I was actually a bit surprised to see EY say "change your outlook on life", which seems very strong. (He did say, "more than" the alternatives, so perhaps it's a bit uncharitable to critique that.)
Acknowledging that its not a substitute for real understanding, I like insight. There's no reason why I can't have them both.
Also, I'm not sure that it is always true that cheep, quick insights aren't the way intellectual growth happens. There have been many little realizations (and even just exposures to new id...
I have started to put together a sort of curriculum for learning the subjects that lend themselves to rationality. It includes things like experimental methodology and cognitive psychology (obviously), along with "support disciplines" like computer science and economics. I think (though maybe I'm wrong) that mathematics is one of the most important things to understand.
Eliezer said in the simple math of everything:
I want to have access to outlook-changing insights. So, what math do I need to know? What are the generally applicable mathematical principles that are most worth learning? The above quote seems to indicate at least calculus, and everyone is a fan of Bayesian statistics (which I know little about).
Secondarily, what are some of the most important of that "drop-dead basic fundamental embarrassingly simple mathematics" from different fields? What fields are mathematically based, other than physics and evolutionary biology, and economics?
What is the most important math for an educated person to be familiar with?
As someone who took an honors calculus class in high school, liked it, and did alright in the class, but who has probably forgotten most of it by now and needs to relearn it, how should I go about learning that math?