This dream is rich in imagery and emotions, reflecting various aspects of your subconscious mind. Let’s break it down into key elements:

1. History Exam: The exam could symbolize feelings of pressure or anxiety about performance in your waking life, perhaps related to academic or personal expectations. The inability to remember if you completed it suggests feelings of uncertainty or a fear of not being prepared for something significant.
2. The Woman and Her Children: Entering the illuminated flat indicates a transition into a new phase or environment in your life. The children, especially the girl who clings to you, might represent your inner child or a desire for connection and comfort. Her statement about moving again might reflect feelings of instability or frequent changes in your life.
3. The Boy and Time: The interaction with the boy who mentions “only 500 hours left” suggests a sense of urgency or impending change. The sadness in his smile may reflect your own fears about relationships or the fleeting nature of certain experiences.
4. Scenic Changes: The shift from foothills to the beach with swirling skies symbolizes a transition from groundedness to a more chaotic emotional state. This might indicate your desire for freedom or escape from pressures, as well as a connection to creativity or beauty in life.
5. Social Media Fame: The revelation that the boy is a popular personality could indicate a longing for recognition or validation. It might also suggest a conflict between how you perceive someone online versus in reality, especially since you have a real-life follower named Adarsh. This could represent your feelings towards social media's influence on personal connections.
6. Searching for Adarsh: Asking your crush about Adarsh and looking for buildings may reflect a search for identity or connection in your romantic life. The rain adding a cold element can signify feelings of sadness or disappointment, perhaps suggesting that you feel lost in your quest for love or connection.

Overall, this dream seems to encapsulate themes of anxiety about performance, a desire for connection, feelings of instability, and the complexities of relationships in both real life and social media.

Advice: Reflect on the areas of your life where you feel uncertain or pressured. Consider how you can find stability and connection amidst these feelings. It may be helpful to engage more with your inner child, seek comfort in familiar relationships, or allow yourself to express creativity and explore new environments.