Dreams about love and relationships can often reflect our desires, fears, and emotions surrounding those themes. In your dream, your classmate confessing his love for you may symbolize feelings of affection or desire for connection, whether with him specifically or in general. The excitement in his confession and your positive response suggest a longing for companionship and romance in your waking life.
The fact that he was never seen again after this happy moment could indicate a fear of fleeting connections or the impermanence of relationships. It may also represent a part of you that fears being vulnerable or getting hurt in relationships.
Overall, this dream could be encouraging you to explore your feelings about love and connection, and it might be worth reflecting on any current relationships or feelings you have in your life. Consider what aspects of love and companionship are important to you and how you might pursue those in your waking life.