He seems to be learning by his mistakes. At least I hope he's learning from them.
I helped him today to fit a door to an alcove. Simple enough, really, except that the walls of the alcove are plasterboard, without any nice chunky bits of wood behind for the fixings. And it's well over standard size, so he's decided to make the door out of solid MDF, which is really heavy.
So, that's two of us there all day to get this thing fitted, and I've left him there to work late painting it up. All for £200 including around £50 of materials. A bit of a disaster, really, except that dad works for nothing.