That's not entirely correct. Yes, the first part of what you say above is the teaching, no doubt, but Buddhists need not take any teaching at face value or just because someone taught it as such-- thus my question should be valid within Buddhist circles. HHDL, for example, teaches that if the scriptures don't mesh with science, go with science.
It's the second part of the above that actually is not correct in that, even what might be part of one's consciousness might not be brought forward completely intact through rebirth. Plus even the whole concept of there being a cosmic consciousness (however worded) to begin with can be questioned.
Part also comes through experience and meditation. However the Dalai also uses the same teaching structure, there is most luckily an example on his website videos, may have to wean through them.
I am Kagyupa, Tenzin Gyatso is Gelugpa. I am stating our concept of it. You are confusing aspects of it.
In Buddhism, the true self, and all of us, have the Buddha nature, the enlightened state. The difference is due to cause and effect, others attributes in experience, many have a clouded concept, and can not see inward. We stride to remove those aspects and break the cycle of samsara. An enlightened being can choose to return. The consciousness and stream is not attached to any physical body. The brain is a receiver to consciousness, and as it develops, is able to handle the stream of consciousness. Teachings are reinforced. Aspects will carry through. If the body has physical issues it may prevent the flow.
However the perception of what is I, or me, is not the same as most see themselves.
AS science develops, and more is learned, more leans to that aspect. If we test and see a change of difference with known fact, then it changes. Buddhists test daily in meditation. Experience, and some Phowa (dealing with death), some of it is cultural, some of it is observation after death., or teachings of Lama's and Rinpoche's
