When I first studied graphics programming, I was traumatized that the coordinate system on a computer’s screen is upside down. The positive x-axis starts on the far left and points to the right as normal coordinates should do, but the y-axis has its 0 at the top of the screen and nosedives straight down to hell from there. Imagine that you have all your graphics worked out beautifully on paper, and then when you try to program it in a computer, you have to flip all the figures and re-calculate all the coordinates. Why can’t computer scientists be normal for once and respect the centuries-old Math? Cartesian coordinates were invented in the 17th century, while the first electronic general-purpose computer (ENIAC) didn’t come out until 1946.