Not a teacher!
You should have posted this question in the "Ask A Teacher" section.
It works a bit like this with "although":
Although statement A is true, situation B happens (you are surprised that B happens; you did not expect it).
Here is an example:
Although he arrived on time at the railway station, he missed the train. - He did everything to be on time and he expected to catch his train. He did not expect to miss the train (surprise).