My grandma calls me up and says "I want to move my computer into the other room, will you come over and plug everything in for me?".

I tell her "the plugs will only fit one way round into the correct sockets, you literally can't go wrong".

She calls me back, saying that her mouse isn't working.

I go over and take a look. She'd forced the USB connector on her mouse into an Ethernet socket with such force that she cracked the network card.

The lesson? Elderly women are strong.