The chapter explores Machiavelli’s formative experiences through the lens of the Aristotelian notion of “impression”, which Machiavelli references in the Discourses on the First Decade of Titus Livy regarding the education of youth. Among the early “impressions” in Machiavelli’s formation are those connected to his modest family environment and the transcription of Lucretius. The transcription reveals Machiavelli’s command of Latin and his affinity with the humanistic circles of Florence. The chapter specifically examines the marginalia left by Machiavelli in Lucretius’s manuscript.