Understanding sustainability worldviews and resulting behaviors is critical to the field of Sustainability Science. As humans face increasingly complex socio-ecological challenges, it is vital to address the lenses through which individuals see the world and act upon. Thus, it is imperative first to understand people's knowledge about and disposition toward sustainability to promote behavioral change. Equally important is acknowledging the cognitive nuances and limitations experienced by individuals attempting to engage in sustainability practices. Studies have shown that cognitive processes, including cognitive dissonance, carry-over effects, moral licensing, and hypocrisy play a significant role in adopting sustainability practices, even amongst sustainability-conscious individuals. In this dissertation, I present a mixed-method exploration of the public's worldviews of sustainability and the cognitive challenges to the adoption of sustainable lifestyles. In my first study, I explore worldviews of sustainability through the development, administration, and quantitative analysis of an online survey. The survey measured five sustainability constructs to explore the sustainability worldviews of a representative sample of the U.S. population (N = 346). Results indicate two separate groups with distinct worldviews: Ambivalents and Sympathizers. Ambivalents tend toward neutral sustainability worldviews, while Sympathizers perceive sustainability more favorably. In study two, I present an analytical autoethnography, shedding light on the attitude-behavior gap in sustainability by focusing on my sustainability worldviews and experiences as a practitioner. Within, I provide an insider's account of the nuances and limitations one experiences while engaging in and striving for a sustainable lifestyle and practices. The autoethnography results reveal the tensions between cognitive processes and the adoption of a sustainable lifestyle. Collectively, my research results offer the sustainability movement insights about possible paradigm shifts toward sustainability based on barriers associated with worldview factors and cognitive processes.