Firstly, I know that I'm totally wrong here and I really regret of doing it.   I'm currently 20 years old - a third-year uni student and over the year, I've been using my brother's 11-15 zip oyster card to save up on my travel, because every day I have to go to my uni in London and it costs nearly £20 each day.   As I don't have student maintenance loans and only rely on my part-time job to pay for my everyday expense, I'm trying to save as much here and don't think