It’s easy to fall into the trap of dumbing down with age. Once you’re out of school for good, learning and growing and exercising your mind can become less of a priority in your life, and it’s easy to feel like you’re not as smart as you were when you were 18.

Of course it’s silly to ever stop learning, when none of us can ever hope to know even a tiny fraction of the knowledge that is already out there waiting for us. Being able to find answers easily by googling something on your smartphone is great and all, but it doesn’t help you develop real skills and in-depth knowledge of anything.

Even if you can’t afford any more schooling and don’t have time to live at the library, there is a wealth of amazing online resources to grow your skills and even your intelligence. Here are some of my favourite absolutely free resources to sharpen up your brain:

  1. Duolingo

Want to learn a second (or third, or fourth) language? Or just brush up on the one you studied back in high school? I’m sure the $500 Rosetta Stone programs are amazing, but personally I just can’t swallow that price tag as a casual, just-for-fun language learner. Duolingo is a fun, easy-to-use alternative. It’s completely web-based and completely free. Currently they offer 14 different languages, unfortunately all European at the moment, but that’s still plenty to choose from. You receive points for doing lessons and compete against your friends on a weekly leaderboard. While I haven’t attempted learning a new language from scratch on Duolingo just yet, I did use it to review and build upon my high school German education and it was great practice and vocabulary building.

  1. Lumosity

Lumosity isn’t designed to teach you anything, exactly. Rather, they compare themselves to a gym, but for your mind. They design games based on the principle of neuroplasticity, specifically designed to “exercise” your brain and literally make you smarter. While there is a fee to unlock the program fully, I’ve personally been using Lumosity for years as just the free version, and still get a lot out of it. The main differences between the pay and free versions is you get 3 games per day rather than 5, and are given a simple “LPI” score (Lumosity Performance Index) to track your progress, rather than having access to a full report of how you are doing in specific areas. Even without the full reports, it’s amazing how quickly the games demonstrate to you your own strengths and weaknesses, and hugely rewarding when you see improvement in areas you’ve struggled with. Taking 10 minutes a day to burn through 3-5 Lumosity games is a fun little exercise, regardless of whether it makes you smarter or not (but they’re pretty sure it does).

  1. Khan Academy

Have you ever realized that things you used to know have just slipped out of your brain over the years? Gun to your head, can you solve trigonometry problems? Or explain the process of mitosis? Do you even remember what mitosis is? Presumably you got through tenth grade, but skills and knowledge you don’t use can just kind of get lost. Last year I decided I wanted to write the Math 30 diploma exam, which I’d never done in high school due to a student exchange program mucking up my course schedule. But I realized that not only would I have to learn the Math 30 curriculum, I was going to have to go back and review from about 8th grade to Math 20 in order to actually understand everything again. This is where Khan Academy was enormously helpful. It is a completely free site that offers an entire K-12 curriculum, complete with excellent instructional videos to explain difficult concepts and exercises to help you practice up your new skills. I completely immersed myself in math for weeks, and I absolutely loved it and felt I understood it better than ever. They also go beyond high school and into university-level education in diverse subjects, from art history to computer programming to health and medicine. I highly recommend checking out this website if there are big academic topics you want to learn about but university courses aren’t in the cards right now, or even if you’re enrolled in an academic program and just need some extra practice.

  1. Codecademy

My husband has been using Codecademy for some time now, and has recommended it to me countless times as a tool to improve my HTML/CSS skills, so I’m a little embarrassed that I’ve just this week gotten into it. Through walking you through coding actual projects, Codecademy teaches you how to program and troubleshoot HTML/CSS, Java, Python, PHP, and more. Afraid you don’t have time to commit to learning programming? Start with one of their “30 Minute Goals”, and see just how quickly you can learn some useful coding to accomplish a simple task.

Bonus Mention:

It’s not free, but I feel this article would be incomplete without the inclusion of Lynda features a huge wealth of information and instruction in software platforms, business and marketing skills, programming and development, and much more. If you’ve got a fairly specific goal in mind, like learning your way around a new piece of software, you may well be able to learn it completely within your 10-day free trial. A monthly membership after your trial has expired is only $20-$35 (depending on whether you sign up monthly or annually, and whether you need access to project files from instructors); that’s a whole lot less than signing up for courses through your local technical college. If you’re unconcerned with certification but want to beef up your skill portfolio, this is definitely worth checking out.