Ever walk into a room and forget why you entered? Or completely space out during an important meeting at work? It’s frustrating, but usually normal.

1. More from TODAY.com
   1. Mom run over by lifeguard truck still recovering
   2. Americans freed by Iran land in Oman
   3.   Redhead? Sperm bank doesn't want you
   4.   Hot trucks may deliver spoiled food
   5. Schwarzenegger to pen ‘Unbelievably True Life Story’

Your brain is naturally primed to wander whenever it can, according to a joint study by Harvard University, Dartmouth College, and the University of Aberdeen in Scotland. Using MRI, researchers found that brain regions responsible for "task-unrelated thought" (that is, daydreaming or mind wandering) are almost constantly active when the brain is at rest or performing a task that doesn't require concentration.

Fortunately, brain experts say it's possible to corral that brainpower, filter out distractions, and master any task by improving your concentration. Here are their top tips for refocusing during key moments when your mind starts meandering, but shouldn't.

At Work
Unless you love everything about your job, you're bound to zone out occasionally, according to one study: Among 124 people, mind wandering occurred about 30% of the time, even during crucial tasks--adding up to many hours of lost productivity. Boredom, fatigue, and stress all spur mind wandering, says study author Michael Kane, PhD, an associate professor of psychology at the University of North Carolina at Greensboro.

And although women were no more likely than men to lose focus, they reported general worrying and anxiety when their attention drifted. Fear not: Some mind wandering is simply your brain taking a healthy break, although sometimes it's best left for another occasion.

Here’s what to do about it ...

Get Organized: If you have several to-dos, decide what to tackle first, and clear all other projects off your desk and computer screen. "Out of sight, out of mind applies," Kane says. "Get rid of memos, e-mails, and anything else that reminds you you're behind."

And go easy on your cubicle's decor. "Even family photos are potential thought stealers," Kane adds, because they're people you're prone to worry about.

Simple steps to take back the clock 

If you daydream during meetings, challenge yourself by thinking of questions and actively joining the discussion, suggests Jonathan W. Schooler, PhD, a professor of psychology at the University of California, Santa Barbara. You may miss a moment if you're formulating a question, but you'll stay focused on the current topic.

Change Your Scenery: When you start to lose concentration, leave your desk and take a walk outside or to the office common space for a mental breather. This way, your brain associates your desk only with work, not mind wandering.

Warns Schooler: "If you don't take regular breaks--especially when you're not enjoying your job--your brain will take them for you."

The simplest way to boost brainpower — spend time outside 

We're most likely to space out during activities we can do automatically, according to a 2006 study. This is dangerous when you're behind the wheel: If a car ahead stops suddenly, your reaction time may not be fast enough to prevent an accident.

Here, 2 tricks to avoid it ...

Tie a String on the Steering Wheel: When you think about the same things during your commute--anticipating the day's workload, or what to cook for dinner--your brain begins to associate the car with zoning out, says Kane. A novel, visual cue such as a colored string or dashboard sticker can snap you out of your "dream-driving" habit.

Play a Game: Those involving counting and geography are great ways for kids to pass the time en route--for good reason: The contests use items that you should be aware of while driving. Try tallying all the states represented by the license plates of the cars in front of you.

Tips to get the cognitive power of someone decades younger 

Do you keep rereading the same passages in your novel? Don't blame a poor memory. "Mindless reading" is common and requires considerable effort to control, says Schooler, who found that readers are actually mind wandering about 20% of the time: "Their eyes move across the page, but they're not thinking about the text," he says.

Fix it with these steps ...

Take a Break: Take time-outs to process the material; mentally recap plot points or a character's motive, for example. "Periodically think over what you've read--it can improve comprehension, probably because it reduces mind wandering," Schooler says.

Go Backward: If you glossed over a few paragraphs, read them in reverse--reordering small packets of information can sometimes change how much of it you absorb. It may feel odd at first, but the extra effort required will force your brain back into

Join a Club: A little peer pressure to finish a book by a certain date can go a long way, especially if you're expected to talk about the content. Budget the number of pages you'll need to read daily, and if you own the book, write notes in the margin and mark meaningful passages to boost both concentration and comprehension.

If You Have a Personal Problem

People who report being unhappy, usually because of a difficult problem, have more intense mind wandering during tasks than their carefree counterparts, according to studies by Jonathan Smallwood, PhD, a lecturer at the University of Aberdeen's school of psychology. These feelings limit your ability to focus on anything else, he says: "You may spend a lot of time thinking about a problem when you're upset, but this type of ruminating is actually quite unproductive."