Brat by Green Day is a punk rock song that conveys themes of youthful rebellion and frustration. The lyrics express a sense of impatience and dissatisfaction with growing up and dealing with parental expectations. The protagonist is eager to break free from constraints and assert their independence. Key themes include adolescence, defiance, and the desire for autonomy. Particularly poignant moments include the blunt expressions of wanting to escape and the sarcastic tone that highlights the clash between the protagonist’s desires and their current reality.