Alexandra Lange has a wonderful profile of Susan Kare in The New Yorker:
Every fifteen minutes or so, as I wrote this story, I moved my cursor northward to click on the disk in the Microsoft Word toolbar that indicates “Save.” This is a superstitious move, as my computer automatically saves my work every ten minutes. But I learned to use a computer in the era before AutoSave, in the dark ages when remembering to save to a disk often stood between you and term-paper disaster. The persistence of that disk icon into the age of flash drives and cloud storage is a sign of its power. A disk means “Save.” Susan Kare designed a version of that disk, as part of the suite of icons that made the Macintosh revolutionary—a computer that you could communicate with in pictures.
Very few designers have impacted the world the way Susan Kare has, and I don’t just say that because I have a dogcow tattoo on the inside of my right ankle.