I'm sorry, but you seem to misunderstand what I am saying.

For one, given that we don't have the foggiest what consciousness is, it seems a little early to say we don't have the capacity to understand it, whatever it may be. Logically speaking, if you say "cannot", this means you have non controvertible proof that there is not any chance this will ever be understood -- this would mean you have exhausted all means and ways of understanding, for a problem where you don't even know what the problem is, exactly. The neurologists and scientists in AI (certainly the latter) are stuck in a paradigm that is indeed wholly unlikely to be the right tool to understand consciousness.

BTW, you keep using the word "can't" where in reality the correct phrasing is "don't". You do not seem to apprehend how strong a claim "cannot" or "never will" is. As a matter of fact, if you can prove that it is in principle impossible to never understand this, this would be quite as miraculous as the magic you keep bringing in. Do not confuse "I don't understand this", or even "nobody understands this" with "this cannot be understood". It is analogous to "we cannot explain this" and "this is inexplicable". The latter claim you can make likely against a background body of knowledge, but proving that this is the final say on it is a whole other kettle of fish. Look up what Kuhn had to say about certain knowledge.

And again: Descartes made no mention of "I"; his phrasing is (still incorrectly, but) better translated to "something is cognized, therefore something exists". To say he was wrong on "I exist" is simply a straw man argument. He made no such claim as far as I can tell; http://suchthatcast.com/cottingham/ has a lightweight introduction to the matter. And even if he did, your "thoughts, not selves" argument still would not bring us an inch closer.

And you should not confuse intelligence with consciousness. These are not even nearly the same thing, and the one doesn't require the other. We have a pretty decent grasp of what we mean by intelligence (when compared to our understanding of consciousness anyway). We really don't even know what we mean by consciousness other than that it is phenomenological. Which is not something the AI folks are at all concerned with. If anyone is going to crack consciousness, it's not going to be the AI people.