Here is my contribution from my personal experience
You should never reverse your car without looking back. Result you will definitely bump into someone's car.
You should never reverse after crossing the traffic lights (if you think you have blocked the road). Result you'll find police car right at your back.
You should never dodge other cars on the main road. Result you are soon going to hit one.
You should never vacuum wet carpet with normal vacuum cleaner. Result you'll soon find out that vacuum cleaner is bust.
You should never sleep before switching off candles which are placed on your window cill. Result - your room will be in flames in no time.
You should never pour bucket full of water outside your friend's door. Result, his carpet will stink like hell later.
You should never hit a man on a motorized scooty in the city center. Result he'll chase you down with his superman bike (scooty)!
You should never leave your work till the last minute. Result you and your friends have to sleep on the floor as some of your friends will hog your bed.
You should never play "beating beating" with a "kiddie baseball bat" amongst your friends. Result it will bruise all over your body and you will not be able to wake up tomorrow.
You should never put a foiled wrapped sandwich in the microwave at 3am. Result - Microwave will burn into flames and Fire alarm will go off and everyone will try to beat the hell out of you.
You should never judge a person by his/her looks. Result you might find that they are much more smarter then you are.
You should never try to flirt with other girls because sooner or later your girl friend will find out and you'll end up spending all night outside in cold.
You should never take a room next to two lovers. Result you won't be able to sleep all night because of the noises coming from the next door room.
You should never play music all night long because sooner or later you'll end up in punishment from the bursary.
You should never spend all your money in expensive restaurants. Result, you'll soon have to sleep with empty stomach.
You should never get your car washed while it's raining. Result you have to visit the "hand car wash" again.
You should never make fun of nerds because sooner or later you'll need their help.
You should never sleep in lectures because sooner or later you have to sit for an exam.
You should never go to lectures 1 hour late. Result the lecture is over and you have learnt nothing.
You should never argue with an intelligent girl because sooner or later you'll realize you started to like her!
You should never help other students because sooner or later you'll find the whole class outside your doorstep.
You should never shout at the teacher because you'll never know he'll go in the washroom and cries.
You should never make a group between girls because sooner or later they'll fight over you.
You should never make a group between your best friends because sooner or later you'll end up doing their work too.
I think my list is getting too long. Will add some more later.