The language stuff is only part true. It's true enough, perhaps, that it's not usually the most important thing to emphasize on a resume, especially if you're

The language stuff is only part true. It's true enough, perhaps, that it's not usually the most important thing to emphasize on a resume, especially if you're doing simple CRUD apps, but nevertheless programming languages and their implementations are varied and complex. Yes, you can become productive in a new language after 6 months of using it, but most people will still have a long way to go before they can claim a reasonably high level of proficiency, especially if there's significant dissonance between the languages. Going from Java (or most languages, really) to Python isn't going to be too difficult, but a lot of that is because Python is a very easy language to get started with. But even with Python it will probably be a lot longer before you really understand some of its less obvious features, pitfalls, performance profile, and are comfortable writing idiomatic code. For a more complicated language, like Perl, or a more distant language, like Haskell, it'll probably be a lot longer.