As a Girl Guide (and before that, a Brownie) I was instructed about the correct way up of the flag. Then, as a teacher, I always had one in my classroom (up the right way of course).
I don't think schools nowadays cover anything about the patron saints, different flags which make up the Union Jack etc.
My husband had to learn all this to pass his Life In The UK test when applying for British Citizenship. Fortunately, I could teach him and he passed.