There is a ditch on my head. What's wrong ~ ~ ~

Everyone has it, both sides have it. Feel it, but the depth is different. This is the gap between the skulls. The exoskeleton of the human brain consists of several pieces with a gap in the middle. This is the starting point of brain surgery. I have one, too. It's okay. Don't worry.

That's the gap between the skulls. Don't worry, it's all animals, otherwise it's not normal.