Turn the music down and pay attention, close your bedroom door and have a sneak peek at what the next thirteen years of your life will bring.
Firstly, your hair is going to change colour multiple times, to orange, pink, purple, red, blue and blonde. It's never going to forgive you for this. Please stop dying it.
I suspect you've been listening to the Manics, and gazing longingly at your copies of Melody Maker (you're going to get work experience there, next year!), imagining life passing you by as you rot in your Fenland bedroom doing your Geography homework. You want to get out, but you're scared of what you'll find. You're scared that you won't be able to cope on your own, without your cosy bedroom to fall back on.
You've just started smoking. YOU IDIOT. You're about to waste the next nine years of your life pissing money away on Marlboro Lights. You conceal your smoking habit from mum and dad for nine years. You think you've got away with it. You haven't. They know. They've known all along.
Recently you've been experiencing feelings of unreality, where you imagine yourself detached from what is happening around you every day. You cry more than is necessary. Getting drunk and stoned is scary and disorientating, and you can't understand why everybody else is so keen on it. Sometimes you're frightened to leave the house. I know all this scares you, but trust me, I've had a lot of experience of all this and you don't need to worry. It's called 'depression'. You'll suffer with it all your life. But you will be fine. Every day of your life from now on is a baby step towards happiness and freedom. Even the days when you feel like you are sliding backwards into despair will teach you a valuable lesson. Try to talk to Mum about this, she wants to understand but she's not sure how to approach you. Dad's not angry with you, he's just afraid.
Don't be so afraid of being alone. Your lonely moments tend to be defining points in your life. You need them to think and move on.
You've got your GCSEs by now, so you know that English is your strong point. Stick with it, it'll serve you well in your future. And pay more attention in Geography, because it'll feature again in your life. You're working harder than you've ever worked because you've realised that the only escape from the boredom of being a teenager in West Norfolk is to get the hell out of there as soon as possible. You're quite right. Keep it up. I won't reveal your grades but you will pass your A-Levels and you will get into your first choice of university.
You LOVE university. Nobody laughs at your clothes or calls you 'weird' (or, worse still, 'original', urgh). You make friends that will stay with you for life. You study Film. You live in a shared house and in this house you find the freedom and acceptance that you've yearned for. Be good to Elin and Anna, they'll take good care of you when you need them the most.
Someone you really fancy off the telly is going to try and have sex with you when you are 26. You knock them back because you've fallen in love with someone else. You think you fall in love at 20. You learn a lesson. At 24 you fall in love for real. He is marvellous, and intelligent, and funny, and all the things you have found lacking in the male populace so far. He gives you confidence and brings you into the light. You move in with him in London and have pets and lots and lots of books and DVDs (they're like videos, only on CDs). He writes comedy for BBC radio, and you are immensely proud of him. I can guarantee you'll still be with him at age 29.
Now, I don't want to alarm you, but I must warn you that at some point in your twenties something bad is going to happen. I've decided not to tell you what it is, because as I look back I wouldn't change a thing. All you need to know is that this event will test you to the very precipice of your soul, but you will cope with it, and you will emerge from the wreckage a stronger and more sympathetic person.
Joe is fine. He never grows out of his epilepsy, but it is controlled, and he has a good quality of life. Maria is fine. You and her live close to each other in London for a few years, and you miss her when she goes back to the North.
You never really 'grow up'. You will feel sixteen forever. But you'll get better and better at being sixteen as the years go by, and your life will sprawl out around you like a rich carpet. It's all going to be okay.