Magic Users
Can't exactly change what you're focusing on when you're sleeping, can you?
That sort of magic is more accidental than anything else where I'm from. Didn't happen all that much with me. Was lucky if it did, really.
Do you go to bed all wound up about anything? Luna told me once that these fluffy, flying little buggers sort of crawl up your nose if you do and get into your subconscious so that they can feed off your Which is absolute rubbish, but