Working on this pattern (a variation of the Morris inspired one below) Illustrator froze up on me several times. I would get ready to export and the program would hang, forcing me to quit and lose any work I hadn't saved. Since most of the time I am so lost in the thicket of the pattern I forget to save. Then when I open it back up I am back in time 30 steps. grrrrr.......
Here's a variation (one of 30 or 40 of these things) for your viewing pleasure. Maybe I'll animate the bunch of them to show the progression of the pattern.
Assuming I learn how to save more often.