I just arrived home from work. I opened the door, picked up a letter lying on the mat, then slung my bag over my shoulder and went upstairs. I got into the study, put the letter down on the desk, put my bag on the chair, and opened the bag. Then I stopped, confused, and wondered why I'd opened the bag.

After some thought I realised that what I had in fact meant to do was to open the letter, but a mental glitch had somehow caused me to mistake which of the things I was carrying I had intended to open – and to mistake it so cleanly and at such a high conceptual level that I carefully put the bag on the chair instead of (as I do when I'm not planning to open it) the floor. At no point did I attempt to treat the bag as if it were a letter; my confusion was not at that level. I opened it exactly the way I would have done if I'd been genuinely intending to open my bag. It's just that that entire intention was the product of a glitch, and the thing I'd been intending to intend (as it were) should instead have driven me to put the bag on the floor and pick up the letter-opener. Very strange.

When I opened the letter, I found I wasn't the only person being strange. The letter was from my bank, regarding a funds transfer I had recently performed via their online banking service, and it said ‘We hereby notify you that we transferred one penny less than you asked for, because otherwise you would have completely emptied the source account and thereby automatically closed it’. This is almost fair enough (though I don't immediately see why it's conceptually unthinkable for a savings account to temporarily contain no money), except that in fact they had transferred £6000.01 less than I asked for! It turns out that the online banking interface handles transfers from this type of account by generating an email to a human, so the human must have manually copied the amount of the transfer from one place to another and got it wrong. Barking mad! I should count myself lucky they managed to get the money into the right destination account, and didn't send it all to Peru.