Back in the 1980s, a group of programmers working on a project called the Demeter system realized that certain qualities in their object-oriented code led to the code being easier to maintain and change. Qualities such as low coupling; information hiding; localization of information, and narrow interfaces between objects. They asked themselves: "Is there a simple heuristic that humans or machines can apply to code to determine whether it has these positive qualities?".
I need to incorporate Demeter Law into my habits, to the point that it becomes second nature ;)