I think I am going to make sure that I do not give up my seat on the train. I really need it to study.
Do you like traveling in the train?
I really dislike all the people who take up seat space on the train just to relax. Other people need it for studying.
While it is expected to give up your seat for somebody who needs it, it is understandable if you don't want to because you need it. Studying is important and it does require you to be sitting after all.
Well good. I will sit on this train.
If you are on the train you are not forced to give up your seat. If you got there first then feel free to continue to sit there. You trying to get work done is a great reason for you to feel the need to have a seat.