Uncle had a nice fountain pen that I thought I'd like to use it but the ink cartridge was empty. It's an old pen so I spent some time wandering around shops and asking questions about the right type of cartridge to buy. At last I managed to find one and took it home delightedly.
I took out the old cartridge and replaced it with the new one. At this point Husband wandered in, picked up the old one and said, 'You realise this is a refillable cartridge, don't you?'
Two points arise from this.
First, the staff who advised me obviously didn't know their cartridge from their elbow.
Second, the articles I read in magazines in the dentist's waiting room about how to make your life more effective - things like allotting dedicated time slots, focusing on one thing at a time etc - don't take account of innate stupidity.
If it were not for that, with my 'brilliant ideas' and optimism against the odds, I could be queen of the world by now undoubtedly.