LAS VEGAS — ON the first day of the fall semester, I left campus from an afternoon of teaching anxious college freshmen and headed to my second job, serving at a chain restaurant off Las Vegas Boulevard. The switch from my professional attire to a white dress shirt, black apron and tie reflected the separation I attempt to maintain between my two jobs. Naturally, sitting at the first table in my section was one of my new students, dining with her parents.

This scene is a cliché of the struggling teacher, and it surfaces repeatedly in pop culture — think of Walter White in “Breaking Bad,” washing the wheels of a student’s sports car after a full day teaching high school chemistry. Bumping into a student at the gym can be awkward, but exposing the reality that I, with my master’s degree, not only have another job, but must have one, risks destroying the facade of success I present to my students as one of their university mentors.

In class I emphasize the value of a degree as a means to avoid the sort of jobs that I myself go to when those hours in the classroom are over. A colleague in my department labeled these jobs (food and beverage, retail and customer service — the only legal work in abundance in Las Vegas) as “survival jobs.” He tells our students they need to learn that survival work will not grant them the economic security of white-collar careers. I never told him that I myself had such a job, that I needed our meeting to end within the next 10 minutes or I’d be late to a seven-hour shift serving drunk, needy tourists, worsening my premature back problem while getting hit on repeatedly.

The line between these two worlds is thinner here in Las Vegas than it might be elsewhere. The majority of my students this semester hold part-time survival jobs, and some of them will remain in those jobs for the rest of their working lives. About 60 percent of the college freshmen I teach will not finish their degree. They will turn 21 and then forgo a bachelor’s degree for the instant gratification of a cash-based income, whether parking cars in Vegas hotels, serving in high-end restaurants or dealing cards in the casinos.