As a young apprentice engineer, I was taught to always hit downwards, with the lead lump hammers we used, to tighten a machine vice.... good advice indeed.... which of course I ignored at 17 years old. These lead hammers weighed about 6lbs, I found out why the advice was so good when I struck upwards to loosen the vice, glanced off the vice handle and bashed myself in the mouth. Luckily for me, once the stars had subsided, I hadn't damaged myself other than my pride.

The 2nd daft thing about it was I still remember my thought process at the time

1. Bash.... what the @#*% happened?
2. Did anyone see me?????

I now and again (about every 18 months-ish) put the ground coffee into the coffee maker and find I've forgotten to put the water in, and as I'm then in a rush I put the water in forgetting that the heater element is now hot. As the cold water is poured in it instantly turns to steam and rushes out onto the dry ground coffee. Result - the kitchen is covered with the dry ground coffee.

It's a bit like when we used to lock cars doors without the key by pressing the button and holding the latch up while you closed it, the door is almost shut when you see the keys in the ignition, but for some reason you just can't cancel the command that's been sent from your brain!

Another one of my stupidities - many years ago when I was but a yoof - the mains lead on one of my radios was too long and kept falling on the floor so I shortened it, next time I put the radio on it buzzed and the valves glowed white hot then it died. --- Note to self dont shorten resistive line cords!

Or turning up for work an hour early because I forgot to turn the clock back or forward, still haven't worked it out.

Gave my brother in law[who was an electrical engineer in the navy]a loan of my brand new electric air pump and he connected them the wrong way round so with a pop and a puff of smoke the brand new air pump was no more.

They train them well in the Navy then.

So very nearly Chronos the Expired!