>> I never developed the intuition for the relevant math

in my opinion, the best way to develop an intuition for the math is through manual calculation (by hand) and by implementing the algorithms/math in code, wax on wax off.

Since everyone making a living in those areas is reusing libraries now many people's knowledge is limited to things they have heard repeated, they don't necessarily have an underlying intuition about the math.

Rayiner, that is really impressive. I personally know I loved programming - but would not have had the fortitude to make it through the theoretical comp sci classes had I been self directed. But oddly enough for me, I favored the theoretical more than the practical classes.

Do you think most people with a CS degree retain sufficient skills in this area to be effective? Maybe PhDs.

Exposure to the CS curriculum at least gives you a leg up in asking questions and working out the shape of your lack-of-knowledge.

Like, knowing that automata and complexity theory exists and remembering roughly how it works means that if something that needs that comes up, at least you have a sense of what you forgot about it.

For instance, having taken a database class where we worked in the relational algebra has helped me fluently write okay SQL even if I couldn't write out a sentence in the relational algebra to save my life.

I’ve never taken a relational algebra class in my life and neither have most dba’s. They learned sql by learning sql.

That's of course a perfectly good way to learn SQL and probably much cheaper. I'm not saying that you need relational algebra to write a query, that would be silly. I just mean that learning that stuff does stick with you.