Well, that was a trek.
I spent Monday night in the hotel QCon put speakers in (the Park Plaza Riverside). The room was very hot. I left the air conditioning set to 16°C overnight and it was loud, but didn't actually cool the room, so I didn't sleep much.
Very tired yesterday and I couldn't face another night of not sleeping, so I decided to check out a day early, skip the speakers' dinner, and go home after my talk (last session of the day).
I made it to Kings Cross just in time to get on the train I'd been aiming for. Only to realise two minutes before it left that it didn't actually stop in Cambridge (I was tired, I mixed up the times of the trains in the two directions). The one I got on went to Peterborough, and a lot of trains to there do stop in Cambridge, but I didn't notice this one didn't until I was on it.
No problem, I got off in time and headed for the correct train. While I was waiting for it to have a platform assigned, I realised something: I had a suitcase when I got on the train, and I no longer had one. I'd put it in the luggage rack above the seats and then forgotten it.
Talked to the platform staff and they called Stevenage, which was the first place it would stop. They agreed to look for it when the train got there and I hopped on the next (very slow!) train that stopped at Stevenage.
Arrived there and they hadn't found it, but they called to Peterborough, where the train stopped and they could do a better search (I wasn't 100% sure which carriage it was in and they'd only looked in the one I thought was most likely).
I then got on the (faster) train to Cambridge. They called me a few minutes later to tell me the Peterborough folks had found it and I could collect it from their lost property office today.
So, this morning, a 40-minute train to Peterborough, five minutes to get the suitcase (yay! They found it and looked after it). Then 40 minutes back.
This has 100% reinforced my belief that trying to do work while tired is counterproductive. The mistakes you make will cost more time to fix than simply doing nothing. I just didn't think that 'going home' was something that counted as work.
The platform staff at the three stations (Kings Cross, Stevenage, and Peterborough) were universally great. Supportive, helpful, and efficient. If I'd remembered which carriage I'd been sitting in when I got off the train, I'd have had the bag in Stevenage.
The processes are not great though. Given the number of trains that go between Cambridge and Peterborough, it would be nice if they'd been able to put it on a train and hand it to the lost-property folks in Cambridge.