Earlier quoted context omitted.
Yes because I know Java (hypothetically I haven’t touched Java since two years after it was introduced) I can become an efficient Android developer “in a few days”. Better yet, since I did Windows CE development for ruggedized devices using C# Compact framework back between 2007-2010, I should have no problem picking up iOS development “in a few days” and start being a productive member of a team right? Or better yet…
Your hyperbolic comment is not far from reality when applied correctly. I've long said, and would stand by: Programming/Development is logic; learn logic. Languages are just syntax; if you understand logic, you _can_ learn the syntax. Taking concepts from one language to another shouldn't be an onerous task. Of course, none of that means you'll get that _senior_ language -focused position, or any particular position…
Guess how long the learning curve was at my next job where I had the learn the intricacies of Win32/MFC, COM and DCOM, when to use which of the 8 different methods that Microsoft had of defining a string and how to safely convert between them, why my C++/ATL COM object kept crashing the other developers VB apps because I wasn’t doing reference counters correctly…