I used to be a happy-go-lucky kind of person. But then, exactly one year ago today, I became a junior doctor: a house officer, a doormat, a sleepless undead zombie, the whipping boy for impatient relatives and work-shy administrative staff. My registrar shouted at me, my patients died on me, my girlfriend left me, and everything was my fault. Then I became a bastard.

But now it's all over, and I'm sad to be moving on. It's a bit like those documentaries about kidnappings and torture victims who, when they're finally released, find that they've developed a sinister and unhealthy bond with their tormenters. I'll miss the fizzy pop crisis meetings at three in the morning with the anaesthetist. I'll miss flirting with radiographers to get my patients' scans done. I'll miss rummaging through a huge folder of crap on the ward round and still not being able to find a good excuse for not having the blood results. Maybe I'll even miss the nurses bleeping me incessantly about pointless nonsense.

And I'll miss my friends, especially for the moments of utter hysteria on weekend ward cover, in the middle of the night, when I called my medical senior house officer for help, practically in tears, no food and no sleep, and presented him with three simultaneous patients all symptomatic with critically low blood pressures and all for no apparent reason. Both of us knew there were several far more messed up patients needing urgent attention at the other end of the hospital, and he whispered: "For God's sake, just write up some fluids and run for your sanity, before they kill you."

Maybe they were all lessons that I needed to learn: because now, I am unflappable. Go on. Try and flap me. Patient vomiting blood with a haemoglobin of six? You'll have to try harder than that. Patient who's found out from a cleaner in the ward that they've got cancer, and a side order of furious relatives? I'll deal with it. Nurses being horrible and calling you slack when you've been busting a gut with no sleep for what feels like a week? Well, with crap like that being dished out, we stopped caring what they think a long time ago.

So, as I pack up my few possessions and prepare to move out of Bedside Manor, the filthy concrete box where they store all the junior doctors at night, I wipe a delicate salty tear from my haggard eyes, and prepare to write a handover list for the wide-eyed innocent young doctor, fresh from medical school, who will replace me.

But the patients are boring, irrelevant, smelly and whiney: the duty of a new doctor is to survive his first year intact, and a duty of an old lag is to help them through. So here are some words of advice for young people.

Rule one: do not piss about. You are a doctor. Do not swear on the wards: instead, comb your hair every morning, and whistle hymns as you go about your day. Your geriatric patients will love you for it: remember to swear about them behind their backs. It will make you feel better about their pain, and your colleagues will cherish you for it.

Rule two: do not piss about. Do not go home on time leaving jobs undone, like everyone else who is not a doctor. You chose the job, now you pay the price. Always check the blood results. Keep perfect jobs lists and do them all, because for every 10 things you forget one will reap disaster. And it will torture you for the rest of your days.

Rule three: do not piss about. Get out out of work as early as possible, whilst still obeying rule two. You are only contracted for 64 hours. Live your life. Grasp every opportunity to get drunk, and have sexual intercourse with multiple casual partners.

Rule four: buy a bloody great big file with loads of pockets. Fill it with everything you need: blood forms, x-ray forms, pens, a pocket house officer survival guide and voodoo dolls of the nastiest nurse on each ward. It will save your life.

Rule five: do not expect to be happy. You will cry. You will hide in the toilets as the patients seem to drop like flies, and you will read your pocket textbook and you will weep. You will feel like you can't go on, more than you can ever possibly imagine, and you will want to die.

Rule six: stop being such a pussy. I'm as clueless as you are. Just get on with it, and I'll see you in the mess in half an hour.