I've thought a lot about this one. It really is the message that matters, not the grammar. It's the song, not the notes.

It's also that language is pretty inherently a very fuzzy, ambiguous, and imprecise thing. If I say, "I've left my cup on the table," then you know what I mean even though you've never seen my cup nor my table. Everyone reading that sentence is equally convinced that it's quite concrete, even though everyone is also imagining a completely different cup on a completely different table.

Even more fascinating, it's likely that nobody that ever reads this post will have met me in person. We have not specifically agreed in advance what our words mean, merely relied upon collective agreement based solely on historic usage.

Honestly, the idea that two people who have never met, never seen each other, maybe never even lived in the same hemisphere, might speak the same language and be able to converse freely is an astonishing feat of magic.