Oops button - what have I done on my computer? Flight recording help

My dear old dad has just rung me as he discovered that his Word document had randomly added red decimal points in between every word and there were lots of backwards Ps in it. He was doing track changes (hence the red text) and had no idea what these markings meant, how they'd managed to appear on his document or what he could do to get rid of them.

So he rang me, as I am utterly brilliant at explaining computer stuff to people over the phone, with hardly any shouting ;)

I explained that he'd probably pressed the backward P button (it's actually called a Pilcrow). Its function on Word is to show you all the spaces and paragraph marks - it can be useful for editing if you're trying to work out why something isn't sitting correctly on the page. It's a lot less useful if it just seems to randomly appear. The 'backwards P' button lives in the Format 'bit' of the Home tab on Word 2010 and pressing it toggles between backwards Ps and no backwards Ps. Problem solved.

We had a chat about the concept of the Oops button which my mum suggested a few years ago. She used to ring me quite regularly to find out what she might have done to her computer to make it look like it was currently looking. This wasn't the same as using Ctrl+Z to undo something (although she made good use of that). Sometimes she'd press a series of buttons by accident and not know what it was that she was trying to undo.

But it should be a bit easier for people to work out what it is that they've done on their computer - Ctrl Z probably doesn't work to toggle backwards Ps on or off.

How can I work out what I've just inadvertently done on my computer?

Dad and I both think it would be a marvellous invention for computers to have some sort of computer in-flight recorder system that kept a rolling record of, say, the last five actions taken and could report this to you when you pressed the Oops button that needs to be invented already.

I have written about this before, here, but I thought it was worth rewriting about rather than just tweeting an old post.

As I use keyboard shortcuts a lot I often press Ctrl+ some other key and if it's not the key I intended to press I can find that I've done something puzzling (eg I once inadvertently opened up some 'inspector' setting on Firefox so that I could see every single thing happening on a web page as it loaded. Fascinating but I had to ask people on Twitter how to unshow it).

It seems like it's got potential as a usability option too - making it that bit easier for people to be less anxious about their computers. My mum found her mousepad / synaptic pointing device a bit too sensitive sometimes and the cursor would occasionally leap to a completely different part of the document she was working on, necessitating an emergency call to IT support, aka me.