Lily - The bad advice fairy

Fairies do exist. You have scientific and even mathematical proof of their existence. And that proof is, mathematically one is more than zero and so one means fairies exist. And that one prefers your left shoulder. That's where she sits most of the time, because the right shoulder is for good fairies who give good advice and she's not that kind of boring fairy. She's also blue and invisible. I know, it's strange to have a color when you're invisible but fairies can do that. You have mathematical proof of that too because one is... well, I already told you about one.