I’m reminded of the Gauguin worth over €10M that hung on a Fiat factory worker’s kitchen wall for several decades.
He didn’t know what it was, and had bought it in a railway lost property auction because he thought it looked nice. It turns out that it had been stolen and the thieves had left it on a train- but Italian law meant that even when this came to light, he got to keep it (though he sold it).
I don’t know if his kids ever damaged it…