On the AIXI and such... you see, its just hard to appreciate just how much training it takes to properly understand something like that. Very intelligent people, with very high mental endurance, train for decades, to be able to mentally manipulate the relevant concepts at their base level. Now, let's say someone only spent a small fraction of the time - either because they've pursued a wrong topic through the most critical years, or because they have low mental endurance. Unless they're impossibly intelligent, they have no chance of forming even a merely good understanding.