There is a kitchen clock at my place. It periodically stops working. Being a sufferer of Duck's Disease (my bum's too close to the ground) I have to clamber up on a chair to grab it and give it a gentle shake to get it going again.
So why does it stop like that? I suggested that perhaps the gears aren't rotating properly, that perhaps there was dust in the internals?
My housemate eventually decided to investigate. It is not like the good old days of tight-wound clock springs waiting to spring free. Surely it would not be that difficult to have a look?
So the back of the little black box was carefully levered off off, only to have small white plastic cogs drop out, the tiny motor fall out, the clock hands drop off - in short, bits everywhere.
We both had a go at reassembling it. I managed to get cogs back in and driving each other in what looked like the right manner. But there was no way that the tiny motor would also fit in that space and the back clip on again. What on earth?
In the end, I decided that it was like a Rubik's cube. Easy to do if you know the trick, mind-bending fury if you don't.
The clock is still in bits, waiting to be replaced.
The best laid plans of mice and men...