It may seem as if everyone has a college degree, but actually only about a quarter of American workers have their bachelor’s. People often attend for a few years and drop out.

But don’t discount the possibility of going back, says Carole Sargent, a teacher at Georgetown University and author of “Traditional Degrees for Nontraditional Students: How to Earn a Top Diploma from America’s Great Colleges at Any Age.”

Sargent answers questions about what it’s like to return to school later in life – and succeed:

Q: What are some of the obstacles adults face when returning to college?

A: Mostly, it’s age, a feeling that college is for kids, that their time is past. Life circumstances can also be an issue, especially for single mothers. And they think they’re not going to have any money. What they don’t realize is that the richer the school, the more likely they are to get money. People also worry what other people will think about them. They’re often stunned to learn that their boss, for example, is actually supportive.

What are some of the assets they bring?

You learn a lot of skills on the job that help you in the classroom, especially if you were doing clerical work. Often people find that being in the classroom is a lot easier than what they were doing in the office. Also, it makes a world of difference when you’re paying for it yourself.

You’re not a fan of distance education, online classes or other “alternative” learning formats targeted at working adults. Why not?

Well, I don’t want to teach them. I like knowing students personally, so I can write letters of recommendation and mentor them. If I don’t know you, I won’t go to bat for you, and I just don’t believe you can really know people through online-only relationships.

Online classes reduce the college experience to its drudgery – writing papers and taking tests. You miss out on all the debate in the classroom, the laughter.

Rich people aren’t sending their kids to online colleges. I’d hate to see in-person education reserved for rich people. The average person has only a very few ways to jump social classes, and an education at an elite college or university is one of them.

What about community colleges?

I love them because they are accessible, but the degrees aren’t necessarily worthwhile. They are a great way to get started, though. Get in there and show you can make a couple of A’s. After that, transfer to a regular school. You need to put yourself in a culture that challenges you.

What surprised you most when you returned to campus in your late 20s, after dropping out and spending a few years working in service and administrative jobs?

That there were other adult students. That I wasn’t the oldest one.

Also, when I got my first A and got off of academic probation.

Cost is obviously an issue for a lot of people. But as you point out in the book, four years of in-state tuition at a public university is on par with the cost of a new mid-sized car. So why do you think people balk at tuition and not a Ford Taurus?

They assume you have to pay for all of it, which isn’t necessarily true. But even if you do, it pays off. Over the course of a career, the cumulative salary difference between someone with a bachelor’s and someone without a degree can be a half a million dollars. With a master’s degree, the difference approaches a million dollars. People need to think of education as an investment.

What’s your advice for people toying with the idea of heading to school, whether it’s for the first time or to pursue a degree they abandoned years before?

Just take one class at first. Make it something you’re good at and do well. A’s talk. When you get good grades, you’ll have an easier time drumming up support from your family and even your boss.