Is there anyone else in this thread who does not have this problem? I don't seem to, and I wonder if I just haven't noticed it. With only the people who share the difficulty speaking up, I don't have a sense of how common it is, and therefore how likely it is that I'm an exception. On the other hand, the "you are now breathing manually" meme doesn't work on me, either, and neither does this observation of Yvain's:

just thinking "I wonder if my face is tingling right now" causes my face to tingle quite perceptibly.

So maybe there actually is a physical difference here.