It's a remarkable occasion, and fans got to celebrate to their hearts' content with the 2-week long event, the '2017 BTS Festa'! Sure, 'Festa' might be over, but for those of you who want to commemorate the anniversary a little longer, how about a little quiz about the boys?

Check below to see if you're an expert ARMY, a soldier just starting out, or just a passerby. And of course, happy 4th anniversary to BTS!