use "some" in affirmative sentence and "any" in negative, interrogative sentence

In general, we use "some" in affirmative sentence and "any" in negative, interrogative sentence. But sometimes I see we can use "some" in negative, interrogative sentence and "any" in affirmative sentence.
Can you please clear this for me?
(If I have any mistakes in writting question, please correct them)
Thanks a lot!:-)

Michael Swan (Practical English Usage, 2005.539-40) writes, "Both some and any can refer to an indefinite quantity or number.[...] Some is most common in affirmative clauses. Any (used in this sense) is a 'non-affirmative' word, and is common in questions and negatives. [...] The differences between somebody and anybody etc are the same as the differences between some and any.'

While there is truth in this, many readers take the remarks about 'some' being common in affirmative clauses and 'any' being comon in questions and negatives to be 'rules'. they are not.

Michael Lewis, In (The English Verb, 1986.34) is perhaps clearer" 'Both some and any are used with indefinite reference.
Some is used if the idea is restricted or limited in some way.
Any is used if the idea is unrestricted or unlimited.
[...] the restriction may be a real one [...]or a psychological one existing only in the mind of the speaker.'

So, according to Lewis,

I like some pop music is limited - 'some' implies that the speaker does not like all pop music.
I like any pop music is unlimited - 'any' implies that the speaker likes all pop music.
I don't like some pop music is limited - 'some' implies that the speaker does not dislike all pop music.
I don't like any pop music is unlimited - 'any' implies that the speaker dislikes all pop music.

***** NOT A TEACHER *****


This is what I was taught:

A man knocks on a door and says:

"Is anyone in there?" = He truly does not know whether or not anyone is in there.

"Is someone in there?" = He suspects that someone may be in there because he heard some noise in there before he

knocked on the door.


*****

Someone pays a surprise visit to your home.

"Would you like anything to eat?" = You are hoping that she/he says, "No, thank you."

"Would you like something to eat?" = A sincere offer from you. You are hoping that she or he says, "Why, yes."