The other answers are correct, but the question goes to something broader. Greek kids will sooner or later find out that a lot of mathematical and scientific symbols used in other languages are Greek, just as they find out that a lot of scientific vocabulary in other languages is Greek.
How do they feel? Unsurprised. They have heard all their lives that Greek culture was the foundation of the West. That their ancestors were building Parthenons when everybody else’s ancestors were eating acorns. Learning about that use of the Greek alphabet just comes to validate that for them.
No, by the way. I don’t think that’s healthy.