Actually, I never get asked that at all! It's a fortuitous coincidence; it was only after I'd gotten the nickname that I realised what it meant in Welsh.

Yeah, German deictics don't line up well with English ones, do they? The conventional way of saying, "I'm here!" is "Ich bin da!" not "Ich bin hier!" The latter actually sounds contrastive to me, as if you're emphasising one location over another. And then there's the curious use of dies hier and dies da for "this one" and "that one", respectively, with jenes basically confined to the Schriftsprache.