I believe the fear of eternal happiness coming to an end caused Monkey to be extremely curious to find out what the future holds. If he can guarantee his own future, and ensure it is filled with health and prosperity, he will be happy to live a life of immortality. Just like humans, the fear of death causes us to change our lives in hopes of prepping for a comfortable afterlife. I wonder, what else might cause him to go on the same journey?
-The article before this one, STORY, also gave segway to this story. The Journey To The West, like the mission of stories described in STORY, had been used to solve unanswered questions of people hundreds of years ago-