> It might be painful to admit, but the practical value of that rather specialized knowledge that took me several years of hard work to obtain is pretty much zero now.

It's sad that your professors didn't tell you beforehand that you were going to learn how to learn during that time, not just study a particular technology stack.

This bears the question- are classes based around studying a particular technology track the most effective way to teach somebody how to learn?

The short answer is probably no. And the fact is that top universities mostly aren't so focused on teaching whatever language or framework is the flavor of the day.

That said, you need tools of some sort if you're going to actually build things as opposed to just learning, say, algorithms in pseudo-code. And it probably makes sense to use some fairly standard language to do so. There's not much point in making things deliberately obscure by making students use some language that the professor designed for his PhD thesis.

Studying math is the best way to improve your logical thinking abilities.

Learning how to learn is a specialized set of skills that weren't taught at the university level when I was in a school.(2010)

I thought that was fairly common knowledge about a great deal of university education.

I bet it wasn't a total waste. The real point of school, particularly university, is to learn how to learn rather than learn a bunch of facts or tools. Attending university probably made it a lot easier for you to switch professions twice.

I learned how to learn way before graduating.

The waste was close to total, but this is only obvious in hindsight. Given the information I had at the time my choices were rational.