I don't have a clue how pointer arithmetic works. I'm vaguely aware of it, but it just never comes up in my professional life. I'm absolutely fine with that, just as I'm fine with the idea that a cardiac surgeon may be vaguely aware of how to perform a kidney transplant but doesn't know the details.
Let's be realistic. The days of wizard programmers single-handedly designing an operating system are gone. We're all specialists now. An embedded systems programmer has absolutely no need to understand the intricacies of XML schema or the finer points of CSS parser bugs. Beyond a broad sketch, I have no real need to know the fine details of memory management.
I'm happy to call myself an ECMAScript programmer because that's what I do, that's what I have done for some time and that is what I expect to do in the future. I know other languages, though none well enough to produce work I would be happy to put my name to (apart from Scheme, but who's going to hire me to do that?). Like it or not, I'm not a computer scientist. I'm a working programmer and my view of the world is inevitably coloured by the raw material I work with every day. The way I think about code, the way I design problems is an imprint of the capabilities and limitations of my usual languages. I imagine a sufficiently literate computer scientist could smell it on my breath, or at least infer it from the way I might sketch out a diagram or pseudocode solution.