I usually let other people take seats before me on the tube out of politeness and not to appear like a complete and utter Toby lost in my own world of headphones and ME novels but this morning as I got on and politely stood up making sure I wasn't blocking the space between the seats some aggro woman got on and elbowed me down with her rucksack whilst pretending I couldn't see her do this. So, when a seat next to her became available I very pettily swooped at it and then had to endure about 20 minutes of her looking at me and her scowling vinegary face fair put me off my book.

Was this a selfish act on my behalf or just me being petty for someone's earlier lack of tube manners?