According to B. F. Skinner, human behavior is motivated by environmental factors, which include people and situations around an individual. The individual can then obtain positive, negative or punishment reinforcements from these factors.
Yolanda was successful the second time because she applied to a college that was closer to her home, where she could have better communication and stand out.
On her first semester, she got high grades and her efforts were encouraged by those around her, in a similar way as when she was in grade school and high school. Thanks to this positive reinforcement, she continued to succeed academically in college and graduate school.