I gave a hasty response when I had no time, so I'm putting an edited version here:
Depends, keypeg. The body of a person with bad habits (like slouching, etc.) will tell that person that correct posture doesn't feel "right". 
Edit:
This was in response to what I wrote, but it didn't catch what I was saying, so it's arguing against something I wasn't trying to say. Let me clarify.
The context is here:
For one thing,
if someone tells you nonsense then you can trust yourself that it's nonsense, and not think you're "doing it wrong".
I was not writing about simply following your senses and self-teaching doing that, because whatever you are used to is the "norm" for you. Thus if you always lean to the left, learning to stand straight will not feel like you're standing straight, it will feel like you are leaning to the right. Thus to feel straight, you would want to lean to the left, which feels straight to you, but looks crooked to anyone else. (For a crude example). I think that's the kind of thing that you are talking about, and I agree.
In the same way, I am learning ways to move at the piano that are totally different from what I have done while self-taught, and some things are quite foreign to me. They are much more effective than what I did "naturally", and over time they will become the new "natural". That again goes with what you are saying.
I was talking about something
different. There are times that we are told something that is wrong, and we go with it out of a sense that teachers are omniscient, all teachers know, and know about everything, and if we sense that something is wrong, then we must be wrong. I had thought I made it clear that this is what I was talking about. We were referring to T. Mark's book, and that one goes into things people were commonly taught in the past, which has given them problems sometimes for decades.
I gave the example where my default way of carrying myself was a type of military posture with shoulders pulled back, a sway back etc. I had already undone some of that. I was told by someone I worked with for a short time to tighten the muscles between my shoulder blades, pull my shoulders back, etc. I had an immediate sense of wrongness, a physical discomfort. This feeling was correct and I should have heeded it. That is what I'm talking about.
On the other hand when I followed a general principal of learning to feel balanced, and started listening to my body, I did improve things. And there are teachers who guide you, who observe and correct, but at the same time encourage you to listen to what your senses are telling you. It is a back and forth.
In the same vein, if you blindly follow any set of rules of how to do things, like you are a piece of Ikea furniture, then you end up missing that connection to your physical self. These are the things I was thinking about. I don't think we are actually in disagreement.