Train etiquette

[speakreveal]

Was on a train from London to the exotic Manchester today for work and had pre-booked a window seat so I could live out my main character moment of glancing longingly at the scenery on my way childrens etiquette training. Sounds great right? Except that I get on the train to see someone is sitting in my pre-booked seat! I don’t do confrontation so I just quietly sat down next to her and stared out the window at a distance but is that normal etiquette to just sit wherever? (I’m not from the UK or Europe and very rarely use the real trains so I don’t really know the etiquette but not to worry, I did still get to see many sheep so it worked out in the end)