> Once you know a paradigm, picking up a new language under that paradigm will
> be just "yet another language", and you can learn one in a week (or 7 in 7
> weeks). Of course, it will take more time to actually become fluent in language
> specific idioms, standard libraries etc, but those are not rocket science either.
I know people who take the same approach to natural language. After all, Spanish and Italian are very very similar, aren't they? The reality with natural languages is that "all languages are the same" thinking enables you to abuse several cultures without actually understanding any of them.
And I think that to a large extent the same thing goes for programming languages. For example, if one of your "paradigms" is "object-oriented", does learning Smalltalk really prepare you for making best use of OO in Java or C++? Or vice versa? The inventor of Smalltalk and OO certainly doesn't think so.
I spent some time a while back trying to explain Scala to a Java programmer. His response was "It's just like Java." Well, Scala *is* just like Java, as long as you ignore the huge and central features that are not like Java. When I started to show him those features, generally in a "replace a page of code with one line" sense, his response was "I don't like it", and that was the end of the conversation. That, in practice, is what "learn 7 languages in 7 weeks" looks like.
My defining experience in this context was observing a government contractor whose preferred language was FORTRAN, who was told he had to code in Lisp. I would not previously have believed that it was possible to write Lisp as if it was FORTRAN, but that contractor proved me wrong. And, to be fair, I find that I have to make a conscious effort not to write C++ as if it is Lisp, eg "everything on the stack and screw the efficiency".
"7 languages in 7 weeks" only works if you stick to programming with the features that can be found or kludged in just about every language. Nowadays that's going to mean procedural code with loads of variables and a bit of OO for accessing libraries. It works, but it's a recipe for terrible, terrible code. But, hey, it will be equally terrible in 7 different languages!