The essential difference between humans and computers is that reasoning itself is a subject of observation for humans.
Reasoning is an inborn ability for humans. All humans can reason though it is not clear what reasoning is. No one grasps the rules of reasoning completely for now. If there were such people, all problems are just a calculation for them. Only clues to grasp the rules of reasoning available are reasoning we did. Humans can gather clues from their reasoning and deepen the understanding of reasoning. It enables humans to get new ideas never imagined.
We need to implement the system that do above things to realize artificial intelligence. It is very difficult. The programmer who implement it has to grasp all rules of reasoning. Some people may say that we can simulate our brain from the neuron level and realize artificial intelligence. However, if such a simulation is implemented, we can grasp how the simulation program generates the artificial intelligence entirely. This is because all parts of computer programs are formally understandable unlike human’s mind.
What I would like to say is that there are no ways to realize artificial intelligence but for to grasp the rules of reasoning one by one. And then, all results of artificial intelligence must give us great insight about how we should reason. Keeping these ideas in mind, I am researching every day aiming to build the ultimate theory.