Parallel Lives and Deaths

Nan Xing has always been someone who likes to let her imagination run wild:

As a child, she thought the whole world revolved around her. Could she be the only one in the world with consciousness? Why did she see others from her own perspective? When she closed her eyes, did the world stay the same? And whenever she remembered the past, why did she see it from an omniscient perspective?

As she grew up, she began to wonder whether this world was real. Could the edge of the universe be made of digital code? Could the real version of her be wearing high-tech VR gear and experiencing a game with lifelike sensations?

Where is the dragon from the Chinese zodiac? Why do all the other zodiac animals exist in reality, but the dragon is nowhere to be found? How many parallel universes are there, and where are they? How can someone enter a parallel universe? Is there another version of her in a parallel universe, and what is that version like?