A few years ago, I had booked a ticket for the scenic train in Norway, between Oslo and Bergen. Paid the supplement for first class (or whatever it is) for the big windows and excellent views, happy days. Anyway, board the train and a while later a lady is asking if I'm in the right seat, so we compare tickets, and both have the same seat allocation, confusion ensues...neither I nor the lady whose seat I'd stolen noticed that I'd booked the tickets for the day before
Luckily the ticket inspector took pity on my idiocy and let me stay on the train in first class, without penalty for which I was eternally grateful (naturally I moved and the lady got her rightful seat).
But wait, it doesn't end there. I get to the hotel in Bergen later on, and there's no record of my reservation...I was a day out on that too, a day early this time
! Luckily there was still space, although I paid a bit more for the privilege of a last minute booking (luckily my pre-booked rate was flexible, and I was able to cancel that just in time).
By this time I was beginning to think my brain had developed a terminal fault. In my defence, I was in the process of changing jobs and selling a house (probably not the best time to decide on a visit Scandinavia really, but there you go), so I think my mind was just elsewhere, but still!