I dreamt that I told my brother about the tunnel people and he said he has experienced it too
Dream interpretation is subjective, but here's one possible interpretation:
Your dream about telling your brother about the tunnel people could symbolize the discovery of a shared experience or belief with someone close to you. Perhaps you feel relieved or validated to learn that someone you trust has gone through something similar to you, or views the world the same way you do. Alternatively, it could symbolize the desire to connect with your brother more deeply, or to share something meaningful with him. Overall, the dream may reflect a sense of closeness and unity with your brother, and a desire for deeper connections or mutual understanding.