Terra Semicognita

If you're looking for something that you've never seen before, how do you know when you've found it? I'm wondering because a few days ago I came across the music of Matthew Herbert for the first time and as soon I heard it, I recognized it as something I'd been looking for.
If this had happened in proper cause and effect order, I might first have thought, "I'm looking for something halfway between They Might Be Giants and Aphex Twin." Then I could have queried something like Pandora or Amazon to find the overlap between fans of each. Though I've never had much luck with those kinds of systems. Usually you get a lot of soundalikes of your seed music when what you want is a non-linear result. Something you didn't know you were looking for.
This sort of thing happens fast and slow at the same time. The recognition itself is immediate. In the first few seconds of listening, I could feel my face forming the "interesting" expression, a furrowed brow with a broad, unconscious smile underneath. This is the face I look for when showing advertising. It's the best immediate indicator of positive interest that I know, more valid and reliable than what people will tell you afterwards. It's not one of Ekman's basic facial expressions, but it should be.
What's slow is the subterranean buildup of information, pushing you towards the moment of recognition. Once I knew Herbert's name, I found that I'd mentally bookmarked references to him for some time, but never remembered his name or did any further investigation  "Oh, he's the guy who sampled all the food in his house. Oh, he's the guy who wrote that musical Dogme thing." With no folder to live in, these bits were in my mind, but invisible.
Really interesting things often feel half-remembered, like a dream or deja-vu. There's a certain amount of pleasant frustration that drives us to find out more, even as we're never fully satisfied that we've grasped it. As if there's a very important personal secret up ahead that's always just out of sight.