I think they mean it that Unicode as a technology should be invisible to the average user. Just as no one should be forced to think about whether numbers above

I think they mean it that Unicode as a technology should be invisible to the average user. Just as no one should be forced to think about whether numbers above 2 billion cause trouble, no one should be forced to remember the differences between Latin 1, UTF-8, UTF-16LE, etc. pp. Normal people just want to write their language and people expect to see what they wrote. If they see question marks, or diacritics next to their respective letters, or completely different scripts, then things failed. But I'd argue that normal people do not need to know how or why that failed. Even for developers with a bit of Unicode experience it's often not trivial to recover text broken in such ways. Oh, and to answer your question: I never learned anything about Unicode in uni either. As for myself, I've been lurking on the Unicode mailing list since about 2008.