“Blame it on the rain”
I see what you did there 😆
As to the length of the passage, it’s not really that I judged by, but the amount of intellectual property contained within a span of words, be they short or long. To me, there is very little, if any, intellectual property contained within the words: I can’t explain, you would not understand.
The only reason I felt different about the longer passages is because of they were easy examples of situations where it becomes more than a common phrase someone also used in a song.
If I said I am, I would not feel obligated to credit it to someone who wrote it down somewhere. However, if I said I am Weasel,I would. It’s one word, but it takes it from what I consider a public domain phrase and makes it specific to someone’s creation:

If I titled a piece I Love Rock and Roll many people are going to jump to Joan Jett (thought it’s not actually her song, she did a cover of an older song), however, even if I were listening to that while writing, I wouldn’t credit that phrase to anyone, unless it related to what I was writing.
On the other hand, I can say i have a Phone, yet iPhone is a protected from brand, so I can’t go around officially calling my Android phone an iPhone even though i have a Phone.
Somewhat different situation, being a trademark/brand/etc. vs. a copyright, but I had to hurry for a example of the shorter ‘phrase’ being the one that would belong to someone/a company/etc.
I was a bit rushed on this, so I hope I’m not babbling incoherently. :D
