Is OTHER wrong in the post ? POST : I've had this friend for a while, who we'll call J, but then I did something horrible (but I don't think that's important or relevant and I don't feel comfortable talking about it) but recently she found me and forgave me completely (this was \~1yr later) and we've been talking for a few days and we've been becoming really good friends again. 

Recently I've been doing mock exams at school which are like pretend exams to practice being in exam conditions. I take these quite seriously because I focus a lot on my grades and want to do well.  I've got my last day of them tomorrow (at time of writing) and J called me, asking if I wanted to go to this environmental protest (she didn't give me much more information other than that it's an environmental protest). I tried to politely say no because I didn't want to skip my exams and idk if I'm the asshole for valuing these fake exams over our newly regained friendship. BTW she got quite annoyed, I think, because I think she was pretending to be fine.