Ordinary performance improvement tips, techniques, and principles that are taken for granted today have their roots in extraordinary research. Today, the learning principle that states that things that occur together tend to be recalled together is widely accepted, and this principle of association as an instructional technique is often used. How did this principle originate? This author, citing the works of Aristotle, Locke, Berkeley, Hume, Hartley, Ebbinghaus, Thorndike, and Kohler, takes an historical approach to highlight some contributions to the principle of association. In doing so, she reminds others that research archives are much more than yesterday's dusty journals. If it were not for this heritage, we would not have the tools, models, theories, and practices that we use today.