It's also not true with respect to people noticing what you've been doing with your career. A programming language isn't just a language, it's also a culture. I've been writing Java professionally for almost 20 years. I can definitely tell when a person isn't a "java programmer." I am struggling to describe exactly what I mean, but the best metaphor I can come up with is it's kind of like hearing someone speak with a heavy accent. It can all be technically correct, the grammar is perfect, but you can still tell it's not native.

Sometimes this is good. It can bring in new/interesting/helpful ways of thinking about problems to come up with better solutions. Sometimes it's bad because anything that's a little jarring or unusual impedes support and maintenance by "native programmers" in the same way a heavy accent can impede communication.