Hmm, are the Brain Fairies in any way related to the beer monkies? Y'know, the ones a friend of mine swears exist, although you never see them, but they take all your money and leave you with Unidentifiable Drunken Injuries... (and have I spelt the plural of "monkey" correctly, because it just doesn't look right...)
Are the Brain Fairies responsible for Fridge Amnesia as well?