My son is an architect with an ability to visualise in 3D in a way that I could only dream about. I can bang out a quick sketch that roughly represents what I want to make, but I lack the ability to visualise all aspects of a complex design in sufficient detail to be able to produce all these sketches at the outset. And my pencil sketches tend not to be that intelligible the day after I've drawn them, and seldom survive very long in the workshop. Add these deficiencies to the fact that I have been known to make mistakes and I prefer to make them on a screen rather than the expensive chunk of Ecocast sitting on the mill table at the moment, and I accept that I am a poor runner-up to those who can go from mental image to finished, assembled, components with the help of no more than the back of a fag packet and a broken pencil.

Still, if the man who never made a mistake never made anything, I should have made quite a lot by now!