Do you think, it's caused by your brain, free from the drudgery of the day-to-day, during meditation?

Not supernatural at all, but I do experience far greater mental capacity.

Not yet, just being present. Reality is what I see in the present, past and future are imagined. I’m not looking for the supernatural nor do I expect it. Awareness can let you see parts of you normally drowned out, it’s nothing supernatural.

Once my head became detached from my neck and started floating away.

Once I experienced what felt like a spiritual fire which was lit in me, right down in the root chakra, which led to an intense out of body experience.
I found it quite frightening. I haven't experienced anything like that since, and I'm not really sure what to make of it.

Another time, I was at my grandfather's funeral, a Quaker ceremony. In Quaker faith and practice they worship mostly in silence, though those who are sufficiently moved by the HOLY SPIRIT are allowed to speak. In sitting in silence in memoriam with my family, I felt a most profound anxiety and knew that if I didn't speak I would feel an unbelievable regret. I felt I had no choice except but to speak, and when I did choose to speak I felt the words tumble out of me, without preparation but with such love and gratefulness for my family. When I finished speaking, I was filled with a... bliss. A feeling of subsuming love and happiness that was nearly overwhelming.

Two closest moments to supernatural something due to meditating or religious context.

'My ex-husband used to see all sorts of crap after three days of dry fasting. Amazing what your brain can trick you into thinking when it's not engaged in doing anything useful....