Building on the qualitative insights collected, this chapter presents the results of a quantitative study examining how consumers perceive the environmental impact and personal sacrifice associated with different high-impact, sustainable behaviours. Using survey data from a representative sample of Italian consumers, the chapter investigated whether people accurately assess which actions matter most for CO2 emissions reduction. Our findings reveal systematic perception gaps. In fact, high-impact behaviours are often seen as excessively costly or disruptive, while low-impact, symbolic actions are overvalued. These results highlight the role of perceived sacrifice in maintaining the marginalization of transformative behaviours in sustainability discourses and narratives. Moreover, our results confirm the persistence of subjective hierarchies that favour convenience over impact. This chapter, thus, provides empirical evidence to support the need for interventions that realign perceptions with environmental realities.