I was just wondering. Human minds are messed up in 1001 ways, but are there a few rational principles that most people already have down? Of course, the answers to this question are probably so extremely obvious that I haven't even considered them. But I ask all the same.
One rational ability that people are really good at that is hard (i.e. we haven't made much progress in automating) is applying common sense knowledge to language understanding. Here's a collection of sentences where the referent is ambiguous, but we don't even notice because we are able to match it up as quickly as we read: http://www.hlt.utdallas.edu/~vince/data/emnlp12/train-emnlp12.txt