I believe people can solve complex problems eventually. By repeated trial and error they will get there; but they need a long time. At this point I agree with Herbert Simon. People do not learn immediately, as those rational expectations models seem to imply. I don't believe that.
The statement that assumptions do not matter is nonsense. It is funny. Yes, I assume people are consistent in their behavior. I assume that not because I believe everybody actually is, but because I believe, on the average, you do not get too far from it.