I don't think so. My problem was that I had a weak grasp of many basics concepts, and more critically I did not know in which areas I was weak. So while it's easy ex post to say "I could skip such and such section", it would have been impossible to make this judgment ex ante.

And in fact, I think a failure mode many people make is trying to predict which things they already know and then skipping those. This allows for blind spots to persist.

I suppose the one way to skip things correctly would be to have a coach. But that comes at a new cost ($), but maybe that works for some people.

I have been seeing more and more usage of 'ex post' and 'ex ante' lately. What do they convey that isn't conveyed by 'after' and 'before'?

it conveys that you know what ex post and ex ante mean

Or, quite often, conveys that you don’t know what they mean.

"Before" and "after" are generic terms. A car might stop before the crosswalk (space). You might eat dinner after work (time). But "ex ante" and "ex post" specify a relationship to an (random) event or to specific information. For example, a data scientist might compute a quantity "ex ante". This means that the quantity was estimated using only forecast data. No historical data was used. It would not make sense, however, to say that a car stops ex ante the crosswalk.

I could have easily said "afterwards" and "beforehand", but I like "ex post" and "ex ante" when referring to before/after having access to specific information.

Got it. I will try to leverage the synergies between Latin and English ex post.

If you, or someone else is seriously considering learning math from the basic at a high level, I’d recommend picking up “art of problem solving, pre-algebra” book, and walking up from there.

These sets of books are universally considered to be among the best math education resources by mathematicians and others, and they start from the very basic (such as the number line and basic operations), but without the need of practicing elementary school material like counting.

I think the TAOPS curriculum would be incredibly challenging for somebody who has actively incorrect intuitions about math.

I think if you've literally never seen the material before, you might be right.

But for anyone who's graduated high school, a lot of it would be at least a second encounter so you'll be reviving forgotten knowledge which is much easier while also diving deeper in your second pass.