So, this just happened in a café I was in.
At the table next to mine sat a group of 3 women who spoke in English with an American accent. I'm just mentioning that because Germany has strict laws on what you can name your child, so I don't think such a discussion would be had by a German.
One had a small toddler. I'm not good with guessing toddler ages, but she was crawling and shakily trying to stand. She came crawling under my table so the mother came over to pick her up and exchanged a few words. She told me her name was Thalia. I said that's a nice name.
For those who don't know, Thalia is the greek muse of comedy and poetry. It is also the name of a big bookstore chain in Germany.
Some ten minutes later I hear the mother talk about how they chose the name. And I kid you not, the explanation was:
She liked Tabea. Her husband liked Delia. So they "invented" the name T(h?)alia as a compromise. She later found out that it's also the name of a German bookstore chain and found it funny. She even made a joke about how her daughter is named after a bookstore now, so I find it highly unlikely she knew about the greek muse.
So TL:DR - Parents think they are clever and making a "new" potential tragedeigh, end up reinventing ancient greek name.
I remember reading a long time ago about a study where a group of artists were individually taken on a ride in a car and then asked to draw a specific thing after they finished the drive. The experimental group was taken along a route that secretly had images planted on the side of the road related to what they would eventually be asked to draw. They found that while those artists didn’t remember seeing the images, what they drew was clearly influenced by them.
I feel this could be a similar phenomenon. Maybe they’d heard the name Thalia in the past and kinda absorbed it without recognizing it as a normal name because they didn’t know anyone with that name.