Murder, mystery and suspense ... these are three words that spring to mind when I recall hanging around staffrooms years ago. Admittedly, I was a groupie. A staffroom groupie. I always wondered: “What goes on in there?”

Mr Beard and Mrs French - they’re a bit friendly, aren’t they? Oo-er, Missus.

Now I’ve been there, the reality is a bit different.

Mug politics can be a serious business. Every teacher has their own mug. This I found was the zen point of the day. Without the mug, there’s paint up the wall, unmarked books and grey hair. Advice to student teachers: get yourself a pack of six mugs (you might actually get to drink from one of them at some point) and be prepared to share. Mugs are personal property, but that doesn’t stop all teachers nicking yours. Lunchtimes in the staffroom can be fun and there’s never a shortage of drama (this is school, remember!).

My former staffroom was divided into two halves, like a football pitch. England versus Saudia Arabia. And someone’s got to lose. In this case it was Sun readers who live on a barge, versus Guardian readers with a three-bedroom semi (usually heads of department and senior teachers). Whoever’s in your staffroom, you need to decide which gang to join at lunchtime. Then the fun begins.

In my first school, at the sound of the bell, all the teachers would run to the staffroom, to be first in the queue for the microwave. I’d warm up my curry, and sit in “my chair”. “My chair” didn’t have “my chair” written all over it, but it may as well; I have given and received looks which say:

“You’re sitting in my chair!” The chair syndrome kicks in after about three years, when you’re just getting comfortable in the profession.

You can never truly be prepared for the staffroom, because, like teachers, all staffrooms are different. I used to leave my lab to go to the staffroom to get some peace and quiet only to have Mrs Shearn babbling eight octaves above everyone else: “That Peter Sellars in 9P! He’s done it now. I’m not going to have him in my lesson again! What do you think, Miss Mirza?” Miss Mirza was miles away with a curry sandwich, trying to get some peace and quiet.

It’s the same with discussing intellectual ideas at lunchtime. There’s always one, isn’t there? Who wants to know how we would achieve world peace and wants a full-blown discussion about it? Student teachers, use some tact here. Teachers need a break. If someone tries to draw you in to one of these discussions, pretend to go and wash your mug.

Then there’s that dreaded “knock” on the staffroom door, when all teachers look up from their sandwich boxes with that Tell-them-I’m-busy-I’m-having-my-lunch face. If you do have to answer a knock for teachers, take a tip from my mother: “Check to see if they want to be in first”.

It took me six months to get used to the social snobbery. You know, the people who won’t talk to you because they’re at the top of the tree in the staffroom. Some teachers are funny like that. “I’ve been here 20 years, you know.” Sub-text: “If you want to join my gang you’ve got to work for a place! I’ve been around a lot longer than you, kid.” After six months they’ll be your best friend.

As lunchtime progresses and everyone is observing who’s eating what or rather who’s eating who, there’s always the voice of a teacher in the background, who makes it hisher objective to reform a thug into an Oxbridge candidate. I always had to listen to hisher progress over my sandwich.

The end of lunchtime is often punctuated with horror. The bell goes and you hear a scream: “Oh my God, not again, I did one last week!” This is the voice of a teacher who has just looked at the cover board. Try to console them.

It’s always a good idea to make friends with the person who arranges cover, to avoid this situation happening to you. On the vacancies board at some point in your career you will see the sign “Head of yearhead of department vacancy”. Underneath it may say: “Let the licking of arse commence.”

At the end of one week I once heard the NQT say “Thank God, it’s Friday” and the corpse that had been engrained into the woodwork for the past 20 years laughed and said: “Weekends! You have to work for weekends in this business.”

Shazia Mirza teaches science sometimes, and is touring nationally with her stand-up comedy show