I was surprised to note a few years ago that it was only my left. This was OK abroad, but I had tp turn my head further (and for longer) in the UK and probably still missed a lot.
I found that I was unable to look over my right shoulder without pain (result of an unplanned dismount some time before).
For the next several months I made myself look right and did lots of silly (and entirely made up) neck and shoulder stretches.
Painful for a while, but now I have the neck of a Barn Owl and canturn 180 degrees in either direction without moving my shoulders one centimetre.
(The last bit is fiction, but the rest is true).