If there is ever a nonvacuous explanation of intelligence, it will explain intelligence by reference to smaller bits of behavior that are not themselves intelligent. But almost everything that goes on in our minds we are unaware of. Still, if the unconscious version yields intelligent results, and the explicit algorithmic version yields essentially the same results, then they will be intelligent, too. I don't even know what a Hidden Markov Model is. The truth is that we have no introspective idea how we recognize spoken words.
Introspection is a lousy way to theorize about thinking.
There are fascinating questions about why we are unaware of so much that goes on in our brains, and why our awareness is the way it is. But we can answer a lot of questions about thinking before we need to answer questions about awareness. I hope I am not taken as saying that all the problems of artificial intelligence have been solved. I am only pointing out one aspect of what a solution would look like. There are no big breakthroughs on the horizon, no Grand Unified Theory of Thought.