In the big knife fight in KoD it talks about how Mat was striking for the parts that bleed the best, then it says something along the line of some of his memories had come from people who weren't very nice at all. If memory serves.

Mat developed the dice thing in book three, he didn't know what it was but, during his POV's it described the occurance of the dice but hadn't realized what it was till later. It was a matter of getting used to the ability the same with Perrin's sense of smell, he could "smell

' emotions but he didn't know what he was smelling. In the later books his descriptions of emotions he smells get more and more detailed.