Consciousness is an interesting thing. The only way to really study it is through self reflection, meditation and awareness.
Stanislav Grof does really interesting work on this subject.
- A brain forming by itself at random is so incredibly unlikely that the known universe as we conceive it (a few billion years old and a few billion light years across) certainly contains no such thing. The point is that it's not infinitely unlikely. So a universe in equilibrium (after the "heat death" of our own, for example) would eventually create such a thing at random. And that this creation, as unfathomably improbable as it is, is still unfathomably more probable than the entropy of the whole universe reversing and creating something like we see now. So the argument is that, if an equilibrium state of the universe is possible, it is actually almost certain that you are such a disembodied brain, rather than the universe existing and your memories being true, etc.
- What it means to live a conscious life? - My thoughts on compassion and living a conscious life.