Kids learn how to pronounce Klara’s name immediately. Even very little toddlers who barely speak start repeating “Klara! Klara!” after hearing me say it. But adults who are sitting right there and who hear both me and their own kids pronounce the name still do the “Clear-ah” thing.
It’s extremely hard to dislodge preconceived notions, folks. Evidence, schmevidence, nobody cares. Everybody lives in their own head. Somewhere on the road from infancy to adulthood, we lose the capacity to allow new information penetrate our intellectual defenses.