Roughly understanding every language is admirable, but very different than being highly productive in a language. If I have to google syntax and packages to do every little thing like writing a for loop, I wont exactly be productive. He is very correct though - subtle differences in syntax often translate well to other languages and learning the general paradigms are the key point.
So yes, have a general knowledge of programming that applies to different languages with ease, but focus on getting very productive with the language that you use all the time. For me, my focus is dictated by my work: primarily VBA, Matlab.
So yes, have a general knowledge of programming that applies to different languages with ease, but focus on getting very productive with the language that you use all the time. For me, my focus is dictated by my work: primarily VBA, Matlab.