Previously, the lower half of the back of my head felt similar, loosening and becoming loose, spreading slightly and feeling like it was moving. Afterward, the upper part of the back of my head also started to move, but there was still a difference between the lower and upper halves. While the lower half of the back of my head was quite loose, the upper half felt like energy was flowing, and there was a slight feeling of spreading, but it was still different from the lower half.
This time, I wasn't meditating, but I was working on a chair in the morning when suddenly the upper part of the back of my head started to loosen. The work I was doing was the same as usual, so it's probably just a coincidence that it started to loosen at that particular time. The previous time, it was during meditation, but this time, it might have started to loosen because it was already somewhat loose, reaching a critical point.
The sensation was similar to the loosening of the lower part of the back of my head before, as it loosened and spread outwards. A little while ago, it felt like it was spreading less strongly, but this time, it feels like it's moving a lot. However, when I touch it or look in the mirror, I can't see any movement, so it might just be a feeling.
This time, mainly the upper part of the back of my head loosened, and as a result, I felt the area near the top of the back of my head loosening as well.
Compared to that, the frontal lobe and the center of the head still feel stiff and like there are issues, but at least, it's loosening gradually and in stages, so it seems like it will eventually loosen completely.
Sometimes, in various spiritual teachings, there's talk like "you must first reach the back of the head," and explanations like how energy from the third eye is channeled into the body, then reaches the back of the head, and finally reaches the Sahasrara chakra, are mentioned in things like the Flower of Life. Indeed, it feels similar to that, and the sequence seems quite similar.
...The next morning, I checked again, and sure enough, the back of my head was spreading, and the spreading caused some muscles in the head that were different from before to stretch. However, it doesn't seem to be a complete blockage, and it stretches accordingly as the spreading movement occurs. It feels like the muscles that were stiff and thick have stretched, and now the finer parts are stretching.
There are still stiff areas in the head, and the area around the frontal lobe and behind the eyes is still stiff, but at least, the back of the head feels like it has loosened. The lower half of the back of my head was loose before, and the condition hasn't changed much since then, but this time, the upper half of the back of my head has loosened significantly, although there are still some muscles remaining, it feels like it has loosened completely.
What remains is the challenge of further loosening the area from the frontal lobe to the back of the eyes, and around the center of the head.
Looking back, similar things have happened before, but the degree is different. Initially, it felt like cracks were forming with sounds like "mishimishi" and "baki," but gradually, it felt like an aura was slowly permeating, like a balloon inflating. And this time, it has loosened considerably, perhaps at a certain stage, and I think there are still stages to go.
Currently, the state is as follows:
・The lower half of the head and the back of the head → A stage less loose compared to before.
・The frontal lobe, the back of the eyes, and the center of the head → One stage harder.
Previously, everywhere was much harder by several stages, but the loosening is progressing one stage at a time, while the location changes.