I've shipped production code in 17 different programming languages. I wouldn't say I'm proficient in any one of them, they are all just tools to solve a problem and the knowledge of language specifics comes and goes. Need to hyper-optimize a DB query on an Oracle RAC cluster? PL/SQL. Need a shader? GLSL works fine. Need a webpage? HTML/CSS/JS. Need to build a 7' long flying robot fish? C. Programming languages are just tools.