The student took a motivation psychology course that taught them motivation is influenced by both internal and external factors. The course covered biological, psychological, and social aspects of motivation including personality, stress, and addiction. The student's favorite part was learning about addiction and the biological and psychological reasons some people become addicted to drugs, such as an innate lower sensitivity to dopamine that makes them more prone to seeking intense pleasure from drugs. Understanding addiction helped them gain insight into why people struggle with substance abuse.