You'd pretty much have to be living on a desert island NOT to know we're deep in the "back-to-school" zone.

If the constant barrage of ads for everything from clothing to computers wasn't a big enough clue, one look at a soon-to-be student (or their parent … or teacher) should have done it. Perhaps you're a student, parent or teacher yourself—which means you've been in countdown mode for some time. However, if you are none of the above, you may think the whole "back-to-school" thing doesn't apply to you.

Maybe it should.

There are as many reasons for going back to school as there are students. Some do it to complete an unfinished degree. Some to advance their current career or train for a new one. Some because … well, because it's there. But here's one reason you may not have thought of:  school is good for your brain.

Hey, I see those eyes rolling! Hold that "Duh!" right there, buster. I don't just mean that your brain gains knowledge by attending classes. Going back to school can actually make your brain healthier. And that's good news when it comes to warding off diseases like Alzheimer's.

How? Let's start with a little Brain 101. Inside your skull is wrinkly mass weighing about three pounds. It has several distinct sections, but is basically divided into two halves, left and right. The left half handles things like math, science, language, and logic. (Think of it as the Mr. Spock of your brain.) The right half is home to emotions, imagination, images, and risk-taking. (That would be the Captain Kirk side of you.)

Then there's the prefrontal cortex: located behind your forehead, it's the bridge of your brain's Starship Enterprise and handles "executive functioning." In other words, it tells your brain—and by extension, the rest of you—what to do. Interestingly enough, this part of the brain is not fully developed until we're into our twenties. (Explains a lot about high school, doesn't it?) The different parts of your brain communicate through little electrical impulses—a kind of mental Morse code.

With me so far? Good. Now when you get up at basically the same time every day, pick up the same overpriced coffee on your way in to the office, spend your day doing the same basic things, then take the usual route home to spend your evening the same old way … your brain gets bored. It's an efficient organ, and once it settles into a routine it doesn't need to use that much of itself to keep going. So when you're stuck in a rut, a big chunk of your brain basically curls up for a nap, leaving the rest to operate on autopilot.

This is not good. If sections of your brain have checked out, they're not connecting with the rest. You may need those parts of your brain later in life—and unfortunately, brains operate on a "use it or lose it" policy.

The good news is, you can wake up your brain. The mental equivalent of a venti double-shot might be almost anything from playing Wii® to a walk in the woods—but one of the best "wake up" tools is to take your brain back to school.

Ann Matt Maddrey, Ph.D., Associate  Professor of Psychiatry at UT Southwestern Medical  Center at Dallas, explains it this way:  "Going back to school helps make those connections in your brain stronger and more intense. It brings in information in a way that you never thought of before."

There are other benefits to slinging on a backpack and heading to class. Your social horizons will expand as you meet other students of varying ages and backgrounds. If you're on the shy side, remember that sharing a class automatically gives you a topic of conversation. While you're chatting about early Romantic poets or the pure beauty of square roots, your brain is making new connections. Dr. Maddrey tells us, "Something physically happens in your brain while you're forming new social interactions."

Not only that, going back to school can make you happier. "I got my Ph.D. as my second or third career, so I'm speaking from experience," Dr. Maddrey says. "At first there's a little angst there, but that's not a bad thing; it will help you push a little harder. Once you get into school, you start to feel better about yourself. You start feeling younger."