Yesterday, Alice and I went to a bookstore*. Standing in line at the cashier was a bewildered-looking woman returning a book.
The title of the book was "iPhone 4 for Dummies". Her reason for exchanging the book was because she bought the wrong version. Her husband told her she had an iPhone 4S, not an iPhone 4.
Let that sink in for a minute.
* A "bookstore" sells stacks of paper with ink on them.