Hi, I Have A Kind Of Strip Along The Top

Hi, I have a kind of strip along the top of my head ranging from one ear to the other where your headphones sit and I'm not sure if that's normal or if I should get it checked out. I've tried looking at images of skulls and they all seem to look smooth but mine goes up and then at to top has a bit of a dip them goes back up again to them come back down to the spine. Is this normal?