Personally I'm only aware of anything behind my forehead when my sinuses are swollen. Like from allergies or a sinus infection. Can cause a headache, or just a feeling of pressure.

Sinus pressure? Your brain has no sensory nerves.

Hmm, no, no infection, no sickness.

Hm, no, it's more above the sinus.

When I meditate I can feel a kind of frequency buzz. Like invisible eyelids of brain waves that shift gears depending on stimulation.

Is it a new sensation or something you've always had? Any pain?

Normal is always a tricky word.

That being said, yeah it's common enough for people to feel things inside their head that normal applies.

It isn't necessarily because you're feeling something at the actual location it seems to be in, but it isn't like there's no sensation in the head's interior. If perception has the sensation placed inside the brain, chances are it's a referred sensation, a trick of the nervous system, but even that's not 100%.

I get some weird sensations when I meditate sometimes, like pressure or movement centred between my eyes, slightly above (the proverbial third eye) and a few inches inward, which would place it inside the brain, if the sensation were coming from where I perceive it to be. And that's not a unusual kind of thing; plenty of people experience similar things during meditation.

When you factor in some of the weird feeling you can get from sinus pressure, nerve stimulation, and shifting blood flow, I'm kinda surprised more people don't talk about it

I feel I always had this. No, no pain.

A information that may be helpful: another friend of mine also has this feeling.