The “mind” is a large, intangible concept, a collection of your thoughts and emotions which drive your actions. These thoughts and emotions are a result of neural pathways in your “brain” — a three-pound organ inside your head that uses about 20 percent of the body’s oxygen.

The brain also affects your body’s functioning. Apart from how you move and talk, the brain controls activities you’re less aware of. Like the flowing of blood, the beating of your heart, and the digestion of your food.

A healthy brain leads to a healthy body and mind. Your body feels energized and suffers from fewer ailments. Your mind feels relaxed and centered, the positive effects of which cascade into your decisions, relationships, and your overall emotional well-being.

This makes exercise for the brain as important as it is for the body. But we rarely do it in our hectic yet mundane routines. That’s the bad news.

The good news is that you don’t need to dedicate an hour for a mental CrossFit. Just 15 minutes a day of the right exercises are enough.

The below list includes seven books I found incredibly useful in keeping my brain as sharp as a 25-year-old, though I’m nearing 40. Their quick, practical exercises won’t just flex your brain muscles; they’ll also add variety to your monotonous routine.

#1. Lateral Thinking by Edward de Bono

Traditional thinking is vertical, which focuses on being right and excludes other pathways. But it limits our worldview by being selective, sequential, and fixed. It keeps us rooted in the status quo.

To expand our worldview, we need to rely on lateral thinking. It generates different approaches, connects unrelated pathways, and discovers new avenues. Creativity, innovation, and first-principles thinking are results of lateral thinking.

Lateral Thinking is a goldmine of simple exercises that fuel such creativity and train you to generate new alternatives, suspend judgment, and build sharper mental models. These exercises put your brain in “play” mode. Even doing three exercises a week will awaken quite a few dormant parts of your brain.

I’ve performed many exercises from the book, yet I’ve just scratched the surface. The best part? When I reflect on my day after completing one of the exercises, I discover better answers to pressing questions.

Machines are better than humans at vertical thinking, at doing what they’re told. To thrive in the future, you’ll need to stop thinking in a tunnel and instead, spot what’s on the peripherals.

You already have the ability to do it. Lateral Thinking will help you hone it.

#2. Ultralearning by Scott H. Young

School taught us that like thinking, learning is vertical and involves rote memory. As a result, it became a dull task we wanted to avoid but had to do. That’s a shame because the process of learning can be stimulating and the results exponential if you apply the 80/20 Rule.

The Rule states that 80% of your results come from 20% of your actions. Thus, 80% of your learning outcomes are a result of 20% of your actions. For instance, being 98% proficient at the guitar demands at least three years of practice. But if you learn 24 guitar chords (which could take just three months), you can play 95% of the songs in the world.

The magic lies in identifying which 20% yields those 80% results, and Ultralearning teaches you to do that. It’s filled with ideas and frameworks that speed up your learning. You can distill a topic to its essence and apply what you learn directly in your work. I’ve used the concepts from the book to improve in many areas, including my Excel skills and even increasing my strength.

Master the art of learning difficult things and you’ll stay ahead of the curve without much effort.

#3. How to Think like Leonardo da Vinci: 7 Steps to Genius Every Day by Michael J. Gelb

Italian polymath Leonardo da Vinci is most popular for the Mona Lisa. But he was also an anatomist, architect, botanist, city planner, cartographer, musician, inventor, geographer, geologist, mathematician, military scientist, musician, inventor, and more.

It’s probably overconfident to think we can become like him, but we can use his principles to tap into our real potential. How to Think like Leonardo da Vinci serves as an excellent guide to embark on that journey.

Michael J. Gelb is one of the most foremost authorities on da Vinci. His seminal book explores the polymath’s life and work, and deep-dives into the seven Da Vincian principles: Curiosità, Dimostrazione, Sensazione, Sfumato, Arte/Scienza, Corporalita, and Connessione. The book offers simple exercises that help you apply each of those principles in various facets of your life, from work to your hobbies, parenting, and more.

I haven’t practiced many exercises from it. In my defense, the book is filled with historic events that make me feel like a child in Disneyland. Each time I read a few pages, I end up researching the names and discoveries mentioned. I feel inspired and ignorant at the same time; inspired because I learn something amazing, ignorant because I realize how much I don’t know.

At a time when creativity and grit are must-have traits, this book will help you discover yourself and become more of who you truly are.

#4. Mega Memory by Kevin Trudeau

The best way to grow is to first prevent losses. Startups should reduce customer churn before they pursue growth; investors should cap their downside before seeking gains; bodybuilders should prevent muscle loss before adding lean mass.

The same principle extends to learning. To get better at learning, you must first get better at retaining. (H/T Readwise for this insight.)

Many people assume they have a bad memory. But the myth of poor retention is just that, a myth. Retention improves with practice, which Mega Memory offers plenty of.

The author Kevin Trudeau was diagnosed with a learning disability at an early age. He was convinced that his problem was his inability to recall information, so he read everything he could on improving memory. Eventually, he developed a memory retrieval program that helped millions across the world, including me.

Each lesson in this book takes less than 30 minutes a day and uses pictures and visualization techniques to activate your memory. No complex associations, no tedious memory systems. The easy-to-follow exercises have improved my ability to recall names, numbers, speeches, and events.

Follow the exercises and you’ll trigger the most rewarding self-improvement program. The ability to recall won’t just let you show off at a party; it’ll also improve your decision-making abilities.

#5. Moonwalking With Einstein: The Art of Science of Remembering Everything by Joshua Foer

Joshua Foer studied evolutionary biology a Yale University and became a freelance science journalist. While researching an article on the US Memory Championships, he got intrigued by the potential of his own memory. After just one year of training under top “mental athletes,” he won the Championship.

Remarkable? Absolutely! Impossible? Not at all.

Like any good journalist, Foer documented his learnings in a notebook, which he turned into the book Moonwalking with Einstein. He trained to memorize information from names and faces to cards, to random numbers. Be he learned much more, like why ancient Greeks said writing destroys memory, and the importance of creating new memories, which “stretch out psychological time, and lengthen our perception of our lives.”

If you’re a stickler for specifics, you might find the book’s title strange. (“Why Einstein?”) But once you overcome that hiccup, you’ll find the concepts of learning are simpler than they appeared in school. They might seem tough in the beginning, but get easier with practice, and can be applied across topics and fields.

Tony Buzan is the inventor of the popular Mind Maps concept (although the technique is like concept maps). The premise of the book is like the two books mentioned above, so I explore it in detail.

But this book is a good place to start if Moonwalking With Einstein and Mega Memory feel tough. Its exercises are simpler and take as little as seven minutes a day. The book also lets you measure your current level and your level after each exercise. Measurement lets you track progress, which makes it the ultimate motivator.

The exercises in Age-Proof Your Brain might too simple, childish even. But think of your brain as a part that’s recovering from surgery. It has been exposed to plenty of distractions and instant-gratification habits that have weakened its potential.

The exercises will let your brain take baby steps so it can get back in shape.

#7. The Genie Within by Harry Carpenter

Almost everyone underestimates the power of our subconscious mind, which is far more powerful than the conscious one. The former makes up 92–95 percent of brain activity, while the conscious one makes up a mere 5–8 percent.

According to Harry Carpenter, the conscious mind has the will and the subconscious mind has the power. When both minds are in harmony, you have willpower and are “single-minded.” But when they’re at odds, you lack willpower and are “single-minded.” And during such a conflict, the subconscious mind always wins. That’s why, when you experience a negative emotion, no amount of rationale or logic can convince you otherwise.

The good news is that the subconscious mind doesn’t need experience to change its perception; it can be changed through imagination. The Genie Within offers exercises to train this subconscious mind, clear your thoughts, and get your conscious and subconscious minds to work together.

I’ve picked two exercises out of it so far that I’ve practiced daily for the last 10 days: one when I meditate after waking up, the other just before I sleep. It’s early to tell the external results, but I feel a tiny shift in my own thoughts and posture already.

What matters more than what you are is what you think you are. As Carpenter wrote, “if you continually think of success, your subconscious mind will guide you to success. If you think loving thoughts, your subconscious mind will guide you to loving relationships.”

Does it sound like a dream life? Then put in the effort to turn that dream into reality.

Summing Up

Your brain is much more capable than you think. It’s more flexible and multidimensional than a supercomputer. It can make unlimited synaptic connections or potential patterns of thought.

Use these books to give your brain a daily workout. I promise it’ll delight you not with tangible results like recalling better and thinking faster, but also with intangible results like a better quality of life.