This dream may symbolize a period of transition and uncertainty in your life. The train represents your journey and the direction you are headed. The fact that it is a local train in Mumbai suggests that this journey may be taking place in your immediate surroundings or community. The train being half-filled with water could represent a sense of being overwhelmed or emotionally flooded in your current situation. However, the calmness of the people on the train may suggest that you are able to handle these challenges with composure and resilience. The sudden change in route and the near collision with a truck may symbolize unexpected obstacles or challenges that you are facing. Seeing your ex-boyfriend may represent unresolved feelings or unfinished business from your past relationship. The flood coming towards the train could symbolize a sense of being overwhelmed by emotions or external circumstances. The panic and urgency to close the door may suggest a need to protect yourself from these overwhelming feelings. Overall, this dream may be reflecting your subconscious thoughts and emotions about a current period of change and uncertainty in your life.