About two thousand five hundred years ago a chap called Socrates would wander around the markets of Athens bothering people. By all accounts he was an ugly, short, unhygenic man who asked impertinent and tiresome questions that few people really wanted to be asked. For that, he has earned the title of the Father of Philosophy.
Socrates' rational was that people didn't question things that they thought were obvious irrespective of whether or not they were right or wrong. If something seemed obvious then it must be obvious. Obviously, this was often not the case, especially in ancient Athens were they believed things like birds grew on tress. By our standards they were crazy. But then, by the standards of someone living two thousand five hundred years in the future we probably believe some pretty ridiculous nonsense too.
Socratic method as it came to be known is the idea that we should question everything that we are told even if, on the surface, it seems ludicrous to. What seems obvious might not be, so without questioning we can't know whether what we believe to be true is or not.
The ability to question, and even perhaps more importantly the ability to withhold judgement until something has been properly examined, is absolutely critical in developing an amazing user experience. If your website is built on untested assumptions you have no way to know whether or not it is really as good as it could be.