I heard in the movie Kubo and the Two Strings:
I do so love the festival.
We just need your other eye. Your grandfather admires it so.
It appears to function as an adverb, possibly meaning very much. Does it have the same meaning as:
We are so going to fail the exam.
If so, I would understand the first sentence, but the second sentence where so appears at the end still sounds strange. What is this usage?