[tester756]

Don't get me wrong, I'm not saying that there's no value in programming languages

I'm saying that programming languages aren't they only way to get familiar with concepts

[RHSeeger]

Nobody said they're the only way. But they _are_ a very good way, for a variety of reasons (which have already been discussed here).

[green_on_black]

I agree, but certain concepts exist strongly at the language level. Like functional programming, Haskell for example: the power of static typechecking along with good type inference, or functional/immutable patterns, or programs as data (IO monad).

Or Prolog and logic-based declarative programming.

Or any GC'd language.

Or a Lisp and its metaprogramming.

I daresay these ideas would be very difficult to see the practical use of, or "impractical" beauty of, without touching the languages.