There is certainly a grand-champion hall-of-famer MOST annoying question, based on how much turmoil it has caused over the last 2,500 years, and based on how easily you can annoy someone with it today, right now.
Thales of Miletus, the “First Sage Of Antiquity” started teaching his students to ask it while his contemporaries were still teaching them to shut up and listen. That basic distinction can still be used to distinguish a good teacher from a poor one, and “the bucket theory of mind” was formally refuted at least 100 years ago.
The ultimate annoying question literally built our world, because of its critical role in the flowering of intellectual culture in ancient Athens, and again because of its critical role in the Enlightenment, Scientific and Industrial revolutions.
One can rightly consider Western Civilization to be defined by the regular and systematic use of this Most Annoying Question (and everyone knows how annoying Western Civilization is to both it’s enemies and participants.) Without those revolutions, our population would still be in the millions world-wide, instead of on its way to topping out at 12 billion, which means that you and I and approximately everyone you know owes their life to Thales teaching his students this most annoying question;
Q: But How Do You Know?
How do I know it’s such an annoying question?
Test it for yourself; try asking it of your child, parent, spouse, boss, employee, salesman, vendor, teacher or student.
If you want to start down the ultimate path, begin with the first thing you can remember.