I only felt my head literally move independent of my neck once. It was whilst responding to a request to stand up straight for an xray. I did a very firm and precise movement to stand up straight (like a sergeant major would, when standing to attention) and it felt like my muscles had lifted my head, moved it back and plonked it down behind where it was previously – it was very weird! So was my xray! The rest of the time, I was never aware of any independent movement.
The pains you describe are usually linked to a build up of CerebroSpinal Fluid (CSF) within the skull causing pressure on the nerves. More often than not caused by restrictions at the cranio-cervical junction (where the head meets the spine). This can be caused by anatomical elements being displaced into the space where the CSF normally flows freely, or by craniocervical instability (CCI) causing intermittent CSF flow restrictions.
Regards
Barbara
(UK)