It wasn't deliberate Scary Woman, was part of the neverending escalation in playground weaponry. A biro tube with elastic band / innertube rubber lashed around the bottom is perfect for propelling cocktail sticks at dangerous velocities towards fellow schoolgoers. I don't remember anyone getting hurt (apart from me of course).
Unfortunately it was I who inheritted the ****wit gene. Pulling the rubber back too far so that the cocktail stick popped out of the end of the birotube resulted in said cocktail stick being propelled diagonally through my middle finger.
(The rubber from a decent quality football is by far the best thing to use, prefereably lashed round the tube with wire, rubber bands barely cut it. Not of course that I'd advocate starting any office warzones...*cough* )