Excessive daytime sleepiness is a consistent and common symptom in sleep medicine. It represents a major public health problem due to its association with significant impairments in quality of life, work productivity, and driving ability. Objective clinical tests for assessing excessive daytime sleepiness follow the universal American academy of sleep medicine scoring classification, which overlooks short intrusions of sleep during wake states, known as microsleep episodes. This narrative review provides a comprehensive summary of the existing literature concerning microsleep episodes, highlighting their significance and potential additional value in the context of sleepiness assessment. Moreover, due to the related attention lapses they cause, microsleep episodes may have significant implications for cognitive performance and road traffic accidents. These are discussed along with potential effective countermeasures. This review concludes by proposing an innovative framework for enriching excessive daytime sleepiness evaluation by integrating the assessment of microsleep episodes into routine clinical tests. Such an approach promises to provide valuable insights into the dynamics of sleepiness and could significantly enhance excessive daytime sleepiness assessment and management through personalized medicine.