He started the program studying Math 33 on campus and has moved onto Math 137 this semester.
Campbell said students in his courses have not noticed his young age. "No one really figured it out," he said. "And if they did, no one said anything."
Arlene Rainey, student services manager in the Office of Continuing Studies, said university courses are useful for younger and more advanced students.
"These younger students simply attend class since they have maxed out in their schools," she said.
But Rainey pointed out that most students in the program are older.
Buie took classes through continuing studies after earning an associate degree at Wake Technical Community College in Raleigh.
He transferred to the School of Journalism and Mass Communication last fall.
Buie said he wanted to experience all that college offers and has been living in a residence hall since becoming a full-time student.
"I see the mistakes that I made too at their age," he said, referring to his hallmates. "But I don't want to be an authoritative figure. I want to treat them as equals."
Sharing a hall with other students has been an adjustment from apartment life, Buie said. He had to adapt to his roommates' sleeping habits and the cleanliness of their room.
He said he enjoys several aspects of University life like celebrating on Franklin Street after a UNC basketball victory or barhopping with other students Thursday nights.
"I have two different worlds," Buie said, referring to his time in class and his social life.
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At 80, Thornton proves that attending college is an opportunity extended to people of all ages. He takes two classes this semester as a part-time student.
Long before becoming a UNC student, he joined the U.S. Army at age 16, where his career took him to Europe in the midst of World War II and later on to Korea.
After his long Army stint, Thornton wanted to experience studies beyond his high school courses.
He said others treat him like any other student without comment of his age. But he said it was difficult to adapt to the constant studying necessary for class.
"I'm envious of these young students whose minds are like a sponge," Thornton said. "I can't imagine taking five classes a semester."
For Zipple, Campbell, Buie and Thornton, attending UNC is simply about education, not about age.
Campbell said he and his professor interact within a normal teacher-student relationship.
"Middle school teaches try to scare you," he said. "But that's not true --(professors) do care."
The Features Editor can be reached at features@unc.edu.