The only way I can explain it is that maybe you were taught your form of magic and not any others. It's a common thing. I don't suppose you know what Coven you belong to, do you?
[Private to Lavender] I see.. You know, you'd think with me being a Seeker and everything, I'd be able to pick that up about her. Thanks for the warning, I won't trust her but I have to learn more about her. It's kind of my job.