As novices we slowly and laboriously sift through a chaotic flood of minutia. To experts the significant details are obvious. Irrelevant details fade to the background. The novice receives a jumble of meaningless impressions; the expert sees patterns and meaning. Experts have made the trek from "How could you possibly tell?" to "How could you not?". And they probably can't tell you how they got there. This talk examines the topic of perceptual learning through the lens of theory and practice—research and anecdotes—and speculates how it can be deployed strategically to train new experts.