Can anyone with a medical background confirm if this is a thing, or folks are just noticing old undulations in their skulls?
You have probably fallen asleep on something patterned or folded and have it leave an impression on your skin before: This is no different.
Other places it happens: Watches that are slightly too tight or have ridden up an arm. Glasses arms pressing against your temple or behind the ear. Tight socks after a day wearing them.
It's not a medical problem. It's just general physics.
I read “soft tissue on top of” the skull to mean more than a superficial skin depression.
We have layers of connective tissue between the skin and skull [1]. Their damage usually calls for medical attention.
