[scottLobster]

I'd say applying said fundamentals is absolutely essential to fully learning them for engineers, and that requires specific technologies, particularly if you're doing anything with hardware. Sooner or later you have to pick a micro-controller and read the data sheets, learn all the vendor tools that come with it, experiment with open source options, etc.

It also depends on your objectives. Are you studying for fun/general improvement or are you angling for a particular job/vocation? If the latter you better be using the tools the job is likely to require.

Not disagreeing that fundamentals are important, they're vital. But I wouldn't say there's "no need" to study specific technologies. You'll never be competitive if all you do is train fundamentals with no applications or objectives. And not all employers are willing to let a new hire "learn on the job". Also technologies do not "come and go all the time" outside of webDev. My knowledge of c++ and Java from 17 years ago serves me well to this day.

[hintymad]

Sure thing. That's why I didn't say studying only fundamentals but "favor fundamentals" and "dive deep in work" and "study model systems". Fundamentals and specific technologies should balance out. I just favor fundamentals in my spare time as they pay more dividend. It may not work for other people, and I don't even know if it works best for myself. It makes me happy, though, which is enough reason to keep me going.