Those who are not as curious, not as interested in learning new things, neither for the novelty, growth opportunities, nor entertainment value, are not to be blamed. Learning actually gets harder as we get older. Our cognitive abilities—that is memory, reasoning and learning—peak when we are teenagers, and may stay strong through our 20s, but then decline as we age. To add insult to injury, as our cognitive abilities diminish, our brains literally begin shrinking.

Brain size peaks at about age 14 when, perhaps coincidentally, we seem to believe we know more than our aging parents. From then on our brains atrophy, lose tissue, throughout our adult lives. “We do fade in a lot of respects as we get older,” says Dr. Robert Epstein, a research psychologist, former editor-in-chief of Psychology Today, contributing editor for Scientific American Mind and author of Teen 2.0: Saving Our Children and Families from the Torment of Adolescence. “We do not know how to stop or reverse this decline, but it is important for us to resist it. There is some evidence that if you keep learning and stay active cognitively, it probably slows down the deterioration. In fact, there is good evidence that people can stay cognitively active even as their brains are deteriorating. It is a cognitive reserve that you can build by staying active.”

In addition to our shrinking brains, most of us take fewer risks as we age, both because of our life experiences and because we do slow down physically. Reduced risk-taking makes it harder to decide to learn something new, even if it is not a physical activity. Plus, routine makes us feel safe. Risk, a situation for which by definition we cannot know the outcome, makes a lot of people uneasy. So, taking risks and breaking out of our comfort zones require specific motivation. That motivation comes in a variety of forms. One is extrinsic, such as continuing professional education, learning a vocation or switching careers. Another is intrinsic, such as learning as a social outlet, as a form of entertainment or out of a spirit of inquiry. No matter the motivation, lifelong learning happens anywhere and everywhere.

Where we learn

“Learning does not have to happen in the classroom. It can and that is great,” says Dr. Bilita Mattes, D.Ed., associate provost for strategic markets, Harrisburg University of Science and Technology. “We have opportunities every day to have conversations and learn. Informal learning is becoming more respected. Lifelong learning happens in many different ways.”

For the curious, those different ways include a host of things like visiting museums, attending lectures, taking learning vacations, reading books, watching videos, engaging in social media, taking online courses or listening to podcasts. And who knows what new media and new learning tools will arise in the coming years.

How we learn

As we get older, the easiest way to learn is to relate something new to something we already know because we have a basis for understanding, a memory that connects the new skill or topic to existing knowledge. If you know how to waltz, for example, it is much easier to learn how to tango than if you have never taken a dance class before. That is comforting for some when considering acquiring a new skill and a perfectly legitimate way to choose a learning opportunity. Unfortunately for our aging brains, that does not provide as much cognitive benefit as learning something genuinely new, something far beyond our current knowledge.

“That is what will do the most good; that is what stretches you,” says Dr. Epstein. “When people learn outside their area of expertise it helps them become more creative. It leads to generation of new ideas. You really want to be learning things outside your current expertise, but that is the toughest kind of learning there is.”

Although there are ongoing debates about how adults learn and whether or not they learn differently from children, it is safe to say that adults bring one thing to the learning process that children do not: a lifetime of experiences. “We learn from our experience and that forms our ideas and how we think about the world and ourselves,” says Dr. Mattes. “Every interaction and experience shapes the way we think and act. As an adult we bring a wealth of experience that allows us to learn, assimilate, question and think critically about what is being presented. That is the fun thing about adult learners—it is not about memorization, they are not passive learners.”

What we learn

If lifelong learners share a trait, it is curiosity—the search for answers or quest for transformation on some level. Age, gender, geography and life circumstances all differ. Statistics are hard to come by because there is no accurate way to track adult education outside the formal world of vocational schools, colleges and universities. As a starting point, according to the U.S. Department of Education, in 2005 there were more than 2.5 million adults enrolled in formal adult education programs. If you consider the informal programs, schools and classes not included in those numbers, as well as learning that takes place via lectures, videos, podcasts, books, vacations and other methods of acquiring new knowledge and skills, the number is no doubt significantly larger and growing everyday.

In higher education, adult learners of all types are one of the fastest growing populations. And there is definite growth in online resources for finding learning opportunities such as TeachStreet, Craigslist, Khan Academy, subject-specific sites to search for culinary or art classes, for example, or sites to identify educational travel opportunities, like Road Scholar.

“We live in a different time,” says Dr. Mattes. “We have the time and means to take classes. And we have access. [Classes] are more easily delivered to us. All those things have changed, and we have so much more opportunity for learning, both formal and informal.”

Lifelong learning is possibly a paradigm for education at all levels. “Education really should be spread out over a lifetime; it should not be that we attempt to cram it into the first 18 years,” says Dr. Epstein. “We should teach young people a love of learning and give them tools to learn whatever they need and want to learn throughout their lives. It would become not just a cool thing a 50-year-old does, but what everyone does, what they love doing and what they are expected to do.”

Go ahead and learn something new. Let your curiosity be your passion, first and last.

Manya Chylinski is a freelance writer in Boston, specializing in education, business and travel.