I like learning new things, and I like learning new old things. I was looking at Apple Human Interface Guidelines from 1987 and this passage caught my attention: The most common use of double-clicking is as a shortcut way to perform an action. For example, clicking twice on an icon is a faster way to open it than clicking once to select it, then choosing Open from the File menu; clicking twice on a word to select it is faster than dragging through it. I knew that double click an icon was a shor...