What did ishmeal mean when he said he lived in three worlds?

my dreams, and the experiences of my new life, which trigger memories from the past. Beah lives for a month in New York. For the first time in a very long time, he feels safe and able to reflect on his life. He is still haunted by nightmares of his time fighting the war in Sierra Leone. He still has vivid dreams that constantly draw him back to the terror of his life in Sierra Leone as a victim of the RUF violence. he lived in three parts of his mind.