Even after his enlightenment, the Buddha experienced suffering. From his teachings and stories about his life, we know that he suffered. But the key point is that he knew how to suffer. His awakening came from suffering: he knew how to make good use of his afflictions in order to experience awakening. And because of this, he suffered much less than most of us.
In the language of neuroscience, enlightenment is the condition of optimal mitochondrial and brain functioning that allows us to experience both wellbeing and inner peace and the urge to create and innovate.
Regardless of the possible number of computations our brain is capable of, the truth of the matter is that most people use most of their computational ability to dwell on everyday problems. This waste of a good brain leaves hardly any computational power for innovation, creative problem solving, and enlightenment.
the false beliefs you have in your head, beliefs so widespread, so commonly held, that it never occurs to you to question them. Because of these false beliefs you see the world and yourself in a distorted way. Your programming is so strong and the pressure of society so intense that you are literally trapped into perceiving the world in this distorted kind of way.