An outstanding issue- after reading "Aleph"

It is said there are paralell spaces exist in the universe. Somehow I belive it right away without thinking too much about the rationale behind.

It is barely for us to bump into starry nights now, though the truth is that we spend less and less time to look the beauties around us. Occasionally, I will gaze at dark blue sky through the windows , the tranquility and serenity will make me wonder what's behind there, apart from galaxy, are the paralell spaces really existing in the universe? If so, can people living in the paralell world can see the same sky as us?

In the book 'Aleph', Paulo shared his self-discovery journey through travel, experiment and reconnection with people and landscape. However, the faith crisis he went through is hard for me to believe and understand. If what he depicted in the book was real, then he was empowered with a superpower to connect with his past life, or, his paralell life experiences, how come a guy