I had just landed in Niamey, Niger, and went for a walk in the market. Niger is very poor so I stood out tremendously. A terribly disfigured person* approached me and begged for money, but I really had none (I do that when I go out in countries I don't know) so I simply had to wave her away. The person said something very loudly and I asked my driver to translate.
"She just put a curse on you".
I obviously paid not attention and went back to camp. I started my laptop and started typing, then realizing there was something wrong going on. Pressed all the frigging Windows Combos, and nothing happened. I shut down the machine and tried a re-start, only to hear the dreadful "ping-ping-ping" of a jammed hard drive. My disk had broken down.
My back-up was, of course, back home. I was in Niger with no machine to talk about, and no way to buy a new one (this was a long time ago and there were no stores of such quality in Niger).
It is the closest I have ever come to believe in witchcraft. And, as you say, the worst possible lesson on keeping back-ups up to date, and with you.