Typically, it will take him more than a month to recognize and regret what he has done, by which time it will be much too late. Furthermore, it is not certain that a guy would have regrets after a month; it may be two months, six months, or even a year. Finally, even if Justin does realize what he has done, he can never get back the love she has lost because of him. The way things are now between them, Jessica will never look at another boy again. She is in mourning for her lost love, and there is no hope of any change until he makes a move first. Even then, there is no guarantee that they will get back together. The most he can hope for is that one day she will go out with other boys and fall in love again. But since she was only 15 years old when they broke up, there is a good chance that she will never date anyone else again.