This is an odd question because I know most of us would go to Hogwarts no questions asked but hypothetically what if a muggle born didn't want to leave their muggle friends or be away from their parents? Or perhaps they were enrolled in another school that they were really looking forward to attending? What if they (or their parents) weren't comfortable with them leaving everything behind to go somewhere that they've never heard of and where they won't know anyone? Remember they are only 11 years old. Anyways, what I'm asking is: Is it mandatory for muggleborns to attend Hogwarts or can they refuse and keep going to muggle school?