When you go to a party and jabber all night long with strangers, you are delighted finding out all this stuff about other people at the time. (what else you going to do?:) The next day you are moody and have a headache maybe. The subconscious can be overloaded. The party can cause a psychic upheaval. In attempting to make sense of the actually bizarre conversations you had the night before, the subconscious has a very difficult time doing this because the fact of the matter is a lot of what you and the people you talked to didn't actually make all that much sense even though at the time it appeared to. Excessive talk overloads the subconscious. It dissipates energy and monks take vows of silence (mouna in yoga) to accomplish the reverse. Silence allows a collectedness. A walk through the forest allows you to unwind some of the endless jabber that constantly plagues your mind.
The inner voice rattles on and on and on in all our waking hours. Like a radio that has been on so long you have forgotten there IS an off-switch. Yogic concentration is about mind control. Deliberately willing thoughts to cease. This does not mean a blank, dull, lethargic staring into space. It means an intense awareness of being in the Eternal Now. In samadhi you are so alive that you can not move. The mechanical thinking mind is like a butterfly trying to swim underwater. Painful for awareness/consciousness to get back into because it is so clunky. And then, to move the physical body - well - that is like the man in the moon. Sure as hell ain't me. Thats the sort of thing you go through coming out of samadhi. You clearly see how distinct you are from both the mind and the body - and a great big smile comes to your face knowing this.
By controlling the inner, the outer automatically comes under control. You are the creator of all you attract. Everything that happens is the result of everything that has happened. Every single electron - even in distant galaxys is doing exactly as it 'should' be.
Theres lots more to this sort of stuff. There is also the sub of the subconscious mind. The sub-superconscious mind. The instinctive mind/instinctive reactions/the aura. There are mystical games like thought watching.
There is something in you that never ever changes. We were never born and can not die