I can muddle along somewhat in French, especially written French, but I have essentially no Polish despite working with more Polish people than French. Nevertheless, Polish is written in a Latin script (for about a thousand years) and so I "can read Polish to some degree". If you show me a Polish street address, and then some street signs, I can spot when the sign matches the address, because I understand that symbols which are slightly different just mean the same thing. If you give me Polish mirror writing, I know it's wrong - it's backwards, even though I don't understand it.

If I attempt this in China it won't work, because I don't understand the Han script, so I am not sure whether a symbol I'm seeing is the same symbol written more or less ornately or an entirely different symbol which just looks somewhat similar. Are the symbols backwards? Or maybe they're different symbols which just look backwards.

The layer beneath this by the way is recognition that intent exists. If you show me Chinese text I not only can't read it I'm not sure which symbols are "the same" and which are not, however I can immediately tell this is writing. The writer intended to convey meaning with these shapes, perhaps I can find somebody else to translate them for me. Whereas say, the pattern on my duvet is just a pretty pattern, it doesn't mean anything (yes, I have thought about this, no it isn't a secret messsage) and so I can't get that "translated".