Did you ever wonder why we put scrollbars on the right? I always thought that they just feel better there because they are a fairly heavy-weight UI component and it makes sense for them to live in a fallow area.
“The Gutenberg Rule, first proposed by typographer Edmund Arnold in the early 1950s, says there are four quadrants on a page: the Primary Optical Area (POA; top left), the Terminal Area (TA; bottom right), the Strong Fallow Area (SFA; top right), and the Weak Fallow Area (WFA; bottom left). The theory says that the eye enters a page in the POA and moves by the most direct route to the TA, via what Arnold calls reading gravity.” — from a Deakin University class
Alan Dix’s article tells a different story. He provides a historical perspective describing systems that positioned scrollbars on the left, and introduces some interesting theories that support the modern convention.