Smartphones and laptops seem so ubiquitous to us all. But in reality, the ubiquitousness we experience every day is based on a series of learned behaviors. Someone once said that, "The only intuitive interface is the nipple. Everything else is learned."
For example, using something as simple as magazine seems like a piece of cake, but in reality a series of interaction involved in using such object is quite complex — as depicted in the parody of iPad reader/ebook apps below created by Khoi Vinh.
Khoi Vinh and Andrew Losowsky poking fun at the failures of magazines on iPad
Often times, conjecturing up an image of known disposition to communicate how a system works is very effective. When Apple released Apple Macintosh 128k, an one of a kind personal computer ever released, Apple introduced a handful of mental models to help understand basic principles such as file system and page scrolling that were not clearly understood at the time.
Apple Macintosh manual - explaining how mouse works
Apple Macintosh manual - explaining how scrolling a page works
Apple Macintosh manual - explaining how file system works