To this day I have puzzled over a third year primary school child who, in a delirious gloating panic, ran up to one of the teachers exclaiming "Miss, Miss, he just said the 'M' word!"

It's no good. Thirty minutes thought I've given to this now, at my employer's expense. Does anyone know what the 'M' word is? - Conor
The magical BBC Micro command that makes keypresses repeat at the speed of light. A nine-year-old genius embedded this in the loader of the shoot-'em-up game that our backward boy was allowed to play. His bewildered grunts as his spacecraft zipped between the extreme left and right of the screen livened up our long division no end.
Fundamental BASIC programming for home computers. An advanced variation was 10 print "Fuck Off" 20 goto 10, and real gurus would put a semi-colon after the closing speech marks.
It's a well known fact that every time you get hit in the head, you lose 10,000 brain cells.

A 1984 experiment to test the efficacy of the claim yielded conclusive proof that it is indeed true. As Sam set about repeatedly hitting precocious upstart Andrew between the eyes, Andrew replied in his excruciating matter-of-fact way "No, no Sam. You've got to hit me much harder than that."

The inevitable ensued.

The joyless track elements of the Track & Field set. Ranging from a short and relatively painless 100m to the soul-crushing infinity of the 1500m, the emphasis on different pacing techniques did little to hide the fact that you were just running in a world where technology had long made running inefficient and unnecessary.
At 100m, the idea was to simply sprint the whole distance. For some this proved to be a matter of bounding heroically - for others of heavier gait, some ethereal custard would drag at our legs. Frustrating when you try your hardest and come last, so you have to feign an effortless defeat. Which is difficult when you can taste blood in your neck.
200m : Also a sprint event; so twice as many children end up red faced at the end. If the fat kid actually did sprint this one, instead of galumphing along in the oblivious lumber of the stubbornly unfit, he was prone to vomiting.
400m : The four hundred metres was the shortest track event to involve a measure of pacing yourself. The fact that you didn't have to sprint with your fingers splayed out like cocktail sticks stuck into a potato was amply counterbalanced by the fact you were running twice as fucking far.
800m : On a course that is a 300m circle, as was ours, this distance allows for the humiliation of "lapping". Watching the sport billies sail past and honking their disdain was irritating enough, but they would also sit down at the finish line and slow applaud the late arrivals.
1500m : Certainly the most annoying race from the mathematical point of view, falling pointlessly short of the 1600m that would have made a perfect geometric progression. After five laps of the 300m circle, it was more than a division between fast, slow and comical. Some would be lapped once, some lapped twice or more. Those getting lapped only once would secretly look down on those getting lapped more often; although they couldn't openly ridicule them, as Sport Billies are very territorial about bullying. The 1500m event would essentially boil down to the entire group watching the extremely unfit and obese kid do the last two laps on his own. A genuine Slim Fast moment.
The combination of my bike lock which I let my friend know so he could borrow my bike to cycle home for a shit at lunchtimes. Such trips were vital to him as he was desparately paranoid about catching aids or gay from the school facilities.
One day, however, I changed my combination and neglected to tell him. The first period after lunch, he stormed up to my desk with his face wet with tears. Slamming his fists down, he screeched "Thanks a fucking lot, Green, I had to shit myself today".
My astonished response was never heard, as it was drowned out by the laughter of some 20 other pupils. A cautionary tale for anyone willing to take responsibility for the toilet habits of others.
The length of Simon Baptist's penis, which he told everyone at every given opportunity. Not in a "My dick's bigger than yours" kind of way, but in a "wow, i'm really happy with the way this has turned out" kind of way.
It's a fantastic time to be alive when someone gets the piss taken for having a bigger dick than yourself.
Game in which you flick a 2p coin at your friend's knuckles and they flick it at yours. The first person to draw blood on all knuckles was the winner.
Missing with the coin and hitting an already bleeding knuckle didn't help you to win, but it did hurt your opponent more.
Shhhhhh, don't cry, have a milkshake.

Now, let's rewind and see each of those elements in action.

1. "Shhhhhh" (Extended middle finger held over the lips)

2. "Don't cry..." (Classic 'V' gesture, with each finger running slowly from just below the eyes to about halfway down the cheeks)

3. "Have a milkshake" (Traditional limp-wristed fist shaking 'wanker' gesture)
The position at the front of a double decker bus, on the right hand side, when you drive through a low-hanging tree. The impact of the tree branches against the bus gives the exciting impression of a 3-D ride to the thirteen children crammed into the one seat, who will scream 3-D RIDE! as they tumble dangerously to the floor.
Role-playing shorthand for rolling three six-sided dice, generating a number between 3 and 18. You use this to generate your "stats" when your character is being created. On no accounts use this term in the real world. People outside your circle of escapist victim friends will not be understanding. Also, never point out that one dice is a die, actually. There's enough bullying without formally asking to be punched.
5 x 5 cm doodles, inspired by the work of the Heidelberg School, a group of 19-century Australian painters who for want of expensive canvasses, once exhibited a series of landscapes on the lids of 9 x 9 inch cigar boxes. A true 5 x 5 is developed from unstructured doodling, making full use of Dali's 'critical paranoiac' method to quickly tap unconscious desires is advised. Generally, little pictures of cocks.
Batty Book Titles are those things that pretend to be real books, but the author is a pun. e.g., "Fell Out The Window" by Eileen Dover. Nicholas Gandolfo never quite got the hang of these, so came up with "Space Rocket Take Off" by 54321 Liftoff. Which is sort of getting towards the idea, even taking into account that he missed the point totally.
I don't think it has ever been established whether the feeling of 6 sneezes in a row equals an orgasm, or if you sneeze 6 times, the sheer power results in uncontrollable ejaculation. When experimenting, do not use an extremely sharp pencil to induce sneezes in art class as it will result in a nosebleed.
The time, scientifically verified to the nanosecond, that it takes to smoke a fag and get to a class.
"Have you got seven minutes before Maths?"
Any mention of this magical number should result in the entire assembly/class moaning with their tongue pushed behind their lower lip and slapping their thigh with their cupped palm. The school never sang hymn number 88, 188 etc. No teacher would dare suggest that the class turned to page 88. As time passed the number of associated trigger words swelled - common words like "space" and "mock" were all that were required to trigger this collective hysteria.