Jaskier: I sing of universal matters, my dear, generous lady. Emotions which anybody could experience. That song could be about anyone.

Yennefer: Mmm.

Jaskier: Anyone.

Yennefer: Mm. Mm-hm.

Jaskier: Anyone. Anyone.

Yennefer: Mm…

Jaskier: Fine. Yes, when I wrote it, it did come from the heart. Perhaps a broken one.

From The Witcher – Season 2 Episode 4: ‘Redanian Intelligence’ (2×04) | TV series produced by Netflix

Quote meaning

Jaskier is talking about the song “Burn Butcher Burn“, where he sings about Geralt. But you know, it could have been about anyone, who’s saying it is about Geralt? Butcher can be anyone, the fact that it rhymes with Witcher is surely a coincidence.