As a programmer, should I know low and high-level programming languages? [closed]

Question

I been contacted to do some work remote controlling LEDs displays over TCP/IP, but my experience and preparation is mostly about high-level programming language. I said that to the person who contact me about the work and he told me that:

"if you call yourself a programmer you should know all these things"

Should a programmer really know the details of low-level programming? Or can I treat it as a black box concept, as theoretical knowledge but not necessarily doing it or implementing low level language solutions, having in mind that low-level programming is not my expertise?