The dreamer’s sister getting married symbolizes a significant change or transition in the dreamer’s life. The lively atmosphere suggests a positive and celebratory event, but the dreamer’s lack of involvement may indicate feelings of detachment or disconnection from the situation. The hall with multiple rooms represents the dreamer’s exploration of different aspects of their life and meeting different people may symbolize the dreamer’s desire for new experiences and connections. The old acquaintance named after someone from several hundred years ago may represent a connection to the past or a reminder of past experiences. The dreamer’s sister wearing a black dress instead of the traditional white dress may symbolize unconventional choices or breaking away from societal norms. Overall, the dream may suggest the dreamer’s desire for change and new experiences, but also feelings of detachment and uncertainty about the future.