This morning, I made ferry reservations for the Octocon weekend in Ireland. All went fine, I entered the dates and times, and gave my credit card details. Back came the acknowledgement, and everything was fine.
Then I started looking at details for the weekend after next, when we intend to make a visit to Oslo. Or possibly Helsinki, I haven't decided which yet, but one of those countries we spotted from above earlier this week.
I think it was about then that I realised that the dates were looking familiar. Yes folks, I paid for ferry tickets for the wrong weekend.
ETA: Tomorrow is 'this' weekend', the following weekend is 'next' weekend, and the one after that is 'the weekend after next'. Don't ask me about the logic or lack thereof. I think that the end of the week in which one is is 'this' weekend, and the end of the next week is 'next' weekend.