Huh. Instant fascination for me - people who can easily make the jump from theoretical knowledge about things to being able to use it in a practical way. My brain does *not* do that easily, if at all. Most of the time, I will need someone to explain the practical aspect of things.
Of course, I'm also fascinated by people who have spatial awareness abilities. Maybe I'm just easily fascinated. :)
*shakes head* I would _not_ have expected someone's reaction to a fractal to cause their brain to hurt, because they were attempting to visualize in their head the process of going into it, infinitely. To me, fractals are pretty. Pure and simple. I mean, I *know* they are infinite, and I have seen the video things which show that fact. But my brain just won't try to *explore* that fact when I see a fractal.
Want to inhabit that brain for a while...