I. We use the mouse not just because Doug Engelbart invented it, but because it turned out to be the pointing device that performed best for pointing and clicking on a display, outperforming light pens, cursor keys, joysticks, trackballs, and everything else that was tried in early tests with users.
II. Years later, when he was searching for a device to select objects on a computer screen, he remembered those notes, and together with Bill English, he built the first mouse.
III. He was bored at a conference, and wrote in his notebook about putting two wheels at right angles to track movement on a plane.
IV. The mouse won because it was the easiest to use.
V. When he was a student, he was measuring the area under some complex-shaped curves, using a device with wheels that would roll in one direction and slide sideways in the axis at ninety degrees.
VI. Doug Engelbart tells the story of how he invented the mouse.