Howard –
A cautionary tale of woe, though not Christmas related, I recall from your Cock-up Number 3) 
And yes that smiley is a deliberate one for a change.
Many moons and Christmases back I was on a caving weekend in Derbyshire, stopping in a local club's rather remote cottage. It had character – electricity from a vintage diesel generating set in an outhouse; and reputedly but not proven the stainless-steel tray acting as sink was an ex-mortuary item. So perhaps in keeping, the pots and pans, especially frying-pans, appeared to be of graphite.
My group returned from our own caving trip to find a rather frosty atmosphere among our hosts. It transpired one member had arrived mid-afternoon, found himself alone so decided to decarbonise the frying-pans. With a wire-brush in an electric drill. Only, he didn't quite finish the task. As one member ruefully remarked about the steak he'd been anticipating,
"It was so covered in aluminium, I couldn't even give it to my dog! "
'
As for wrong change-wheels, my Harrison lathe has a special Thread Cock-up Feature. Its power-feeds and lead-screw are both driven from the change-wheels through a 3-speed gear-box. Took me a long time to discover it wasn't my arithmetic….