Emotions provide a ubiquitous and consequential backdrop to daily life, influencing everything from physiology to interpersonal relationships in the blink of an eye. Instances of emotional experience accumulate and compound to impact overall mental and physical health. Under optimal conditions, emotions are adaptive for the successful navigation of daily life. However, situational features of military life likely amplify everyday emotions and their impact, creating the need for soldiers to have a well-oiled emotional resilience system in place from the start, to be maintained throughout their careers. Basic research in affective science has identified the active ingredients that would be required in order for such a system of skills and abilities to have maximum impact on overall emotional fitness. Results of this emotional resilience training may provide compounding benefits for the individual as well as have spreading impact for the benefit of the military unit and other social connections. The Comprehensive Soldier Fitness initiative highlights important new frontiers in affective science and presents a challenge to our field that requires taking a second look at the theory-testing process. (Contains 1 footnote.)