Answer:
the primary purpose of that is to show everything have both a good side and a bad side also to show that not everything is what you think. It also explains some of the good old days stuff like in the book it first describe as feeling nice and warmish then starting to hurt
Explanation:
1st- is a noun phrase
2nd- not a noun phrase
3rd-is a noun phrase
4th-not a noun phrase
hope this helps!