I think the sign "Stop hurting yourself" means that most people now hurt semselves but not literal but hurting thier lives. I think the teacher put it up on the board because most teens now are hurting themselves. For example we are just letting our education go by us with out trying to get one. Also most of them throw away their lifes and they are only hurting themselves. I have a friend who just tought coming to school was pointless. He never did anything in school. He decided to quite school and start working and got his gf pregnant when he had a good oppurtunity to study. Now hes 23 and is still working and has to work 2 jobs to maintain his family. And he regrets ever quiting school