The feeling of superiority is what makes humans feel good and there are many different ways. One of the ways to get above others is by insulting the other person. Regardless, the words were just sarcasm. But that was already given the feeling of victory over others. For the person who has done it and achieves the goal, the person may quickly forget after that.
However, for the victims, it's a completely different story.
Feelings of fear, hurt, embarrassment, embarrassment, insecurity. Many of those feelings leave a gaping wound in the feelings of the victim. A cruel act that does not leave a wound on the outside but inscribes an even more brutal internal wound and never be able to heal because that feeling will remain in that person's memory forever.