In any case, Elisa, believing in ghosts and to be scared of a surname, it makes suspicious that there is a problem and that problem doesn't come from the surname itself.
You will agree with me that any person that values other person through his surname is, at least, immature. The reasoning, "this surname is nice, he must be good person, this another one is ugly, he must be a bad person " is a total immaturity.
Well... If he was called "Count Dracula", then you'd be right. But this is a fantasy case.
I hope you do not mind but the things what you say it makes me think that you're more than a teacher, a pupil.