You never truly know anything until you have first hand experience. This must be obtained by personal trial and error. Reading textbooks and believing what you read is no different than believing in Santa Class or the Tooth Fairy as a child. It's only a belief at this stage.
Me personally don't believe anything until I have personally conducted my own testing. For many layman audiophiles, they simply don't have the knowhow to conduct the necessary tests to truly know what matters. So the next best thing is to just trust your ears.
Trust is usually something that applies between people. If I say "I trust you", I usually mean: "I accept what you are saying as true, without double checking". Similarly, when I hear "trust me!", I realize that it is expected from me to accept the veracity or sincerity
without double checking. In real life, this sort of trust is most important between people who deal with each other regularly and on an equal level. If some stranger asks me to trust him, I would be much more skeptical; even more so when it is a politician.
If I hear "trust your ears", it sounds strange at first, because I'm supposed to trust something that is not a person. This might be a sign of animism, where things are believed to have "a life and will of their own" (and I have long held the suspicion that many audiophiles might actually be animists, judging from the way they talk about gear). More likely it is supposed to mean: "Accept the first interpretation of what you perceive, and don't reason about it nor try to check it".
We know the subconscious can be "primed", and with it the interpretations it produces. Whoever tells us to trust our ears, trusts that our subconscious is primed in the right way according to
his preference. That's a hidden agenda.
But in reality what value is there in "trusting one's ears" in this way? What is bad about checking when one has doubts? When audiophiles often say "trust your ears" that is precisely what they aren't doing. They are trusting a whole lot more than their ears. They are trusting their expectations, prior knowledge, sight etc, so clearly the idea of "trusting your ears" is a fallacy as often claimed because that's not at all what people are doing.
If people were forced to discern sound using their ears and only their ears without other variables influencing the results - ie blind listening - then that would be far closer to "trusting ears" because that's literally all you
can do.
