We should forget the past and live at present

Are you still regret for your past time, are you still feel you didn't do well in past (D3 Gold), just forget all of these and start the new life, we should live at present, not recall the past things always. Maybe you didn't study very well, you don't want to hear any instruction from your teacher and parents, and you feel they are so annoyed, you don't want to do anything as they wish, you just want to do as you wish, you always thought your teacher and parents are square-toes, you don't want to hear anything from them. You don't want to study, you always have many ways don't go to classroom and stay at bedroom sleep, or just go to net bar spend all your night and day. You have many a little contradiction with your classmate, you always get the little chance tell their mistake to teacher, you feel so happy when you see your classmates been blamed by teacher, from then you have a so called enemy in school, you are even throw your classmates' book and some other things, you are still feel happy when you see your classmates worry about their book. You never thought you are classmates, you should learn to get well with your classmates, you are doing all these boring thing in all your school time. But now, you grown up, you feel you are so childish and bored in past, but you just can choose forget all of those.