...AND

In any of these modes, yes, it can be a great comfort to wear one. It signifies to your brain that you are not astray... that you are where you belong.

Why this is so may be beyond our ability to accurately describe. It may be because we choose to describe it with comforting language that we call to mind at the feel of the collar around the neck...

or (in my case) the tension on the leash attached to the collar.

It may be because somewhere back in our neolithic memories, the sharing of clothing meant you were part of the tribe, safe and secure, not alone.