Perpetual student

A perpetual student or career student is either a college or university attendee who either pursues multiple terminal degrees or re-enrolls for several years more than is necessary to obtain a given degree.

For the first category, perpetual students might publish or work in several fields and are often considered polymaths.

As for the second category, as early as 1545, Christoph Stymmelius in his play Studentes explore the concept of students who go offer to university and instead of being diligent in their studies engage in debauchery.

Long tenure to complete a single degree

 * Milton De Jesús has been a student at the University of Puerto Rico since 1963. In 2010, De Jesús was interviewed by the newspaper, since he was the only student on the campus who could compare the 2010 student strikes and the 1970s, 80s, 90s, and 2005 strikes.
 * Johnny Lechner attended the University of Wisconsin–Whitewater from 1994 until at least 2009. He spent 13 years as a senior at the university.