I don't think you have to be friends with your co-workers, it would be nice to be friends with them but I wouldn't want to feel obligated to be friends with them. I feel that you should have the choice to make your own friends. It's great to have friends, someone to make jokes and have fun with. Being friends with a co-worker could be distracting they could keep you from finishing your work. I think that you don't really need to be friends with your co-workers but it's all up to what you want. Over all I would want my co-workers to be my friends but I don't want to feel forced into it.