This essay argues that while the so-called "Hume's Early Memoranda" has long been regarded as Hume's juvenile work composed before A Treatise of Human Nature, there is significant internal and external evidence to the contrary. M. A. Stewart's recent thesis made a new attempt to move the period of composition to the early 1740s. I seek in the following essay to date the composition even later, in the latter half of the 1740s. Re-examined in this new light, the memoranda credibly emerges as a work of preparation for Hume's political economy to be published as Political Discourses in 1752. Historical and biographical details thus reconstructed around the process of Hume's composition of the memoranda reveal the hitherto-unrecognized complexity with which Hume's economic thought was gradually formed in close and profound connections with his moral, political and historical thinking.