My art teacher at high school, the amazing Mr Carberry, used to assign his first year pupils the task of drawing a bike from memory. He'd give everyone a piece of paper and a pen and tell them they had 15 minutes to draw a bike. Go!

When the time was up, Mr Carberry would gather the class around his desk and flick through all the work. The drawings were, as you'd expect from a class of uninterested 13 year olds, all over the shop. Everyone would laugh as he pointed at the twisted frames, the mismatched wheels and the precarious saddles.

He'd then give us a brilliant wee demonstration on how, with a little thought, a bike will almost draw itself. "Well, you need two wheels, don't you?" he'd say, "and you'll need to be able to steer, so that must mean the handlebars are attached to the front wheel." With a quick few strokes, he'd explain that the pedals must be where your feet go, the seat must be where your bum goes, join them up and, bang, there's your bike.

It was a great little lesson that has stuck with me for well over 10 years now. It was interesting, funny and inspiring. It helped that Mr Carberry was a proper beret wearing, baldy headed, moustachioed, mad-as-hell art teacher too. There are a thousand more of his lessons that are worth mentioning, but this one just came to mind. Today I drew a bike that came out wonky and it took me right back to high school.