For years and years I taught 3D computer modelling and animation to architects and interior designers. As you probably know, when you have been teaching something difficult for a while you start to see the same mistakes over and over again. It’s easy, dangerously easy, to forget that it’s new people making these same mistakes and get, well – grumpy.

A student taught me this important lesson one day in a computer lab. I don’t even remember what I was trying to teach her, but I do remember she was an infuriatingly slow learner. My impatience grew till eventually (I’m ashamed to admit this) I literally grabbed the keyboard out of her hands and said something like “No no no! You do it THIS way”.

To this student’s credit she didn’t let me get away with this. In front of 20 of her classmates she reminded me that my…