There is not only one thing that can be solved online.
Everyone has at least three dreams every night, and sometimes he doesn't know that he had a dream, which belongs to a sleeping dream.
Ordinary dreams only reflect their inner thoughts unless they want something. It doesn't make any sense.
As mentioned above, it is omnipotent to be the Monkey King and the Great Sage. Maybe LZ thinks he subconsciously wants to be or has the ability like Sun. According to the introduction, LZ has some obvious inferiority to himself at present because of some things, or is currently in a state of smiling. The former is more likely.
It is an old saying that the Monkey King helped Tang Sanzang to study in the North, which is close to "failure" and also a bumpy road.
The main idea of the dream is to teach by example: there are many ups and downs in life, even if you encounter some gratifying or unsatisfactory things, don't pay too much attention, and those who are tolerant can last forever.