Tell me if you've heard this one: A neuroscientist, a Greek philosopher, and a Tibetan monk walk into a bar. They start talking together and all of them agree on one thing: that it's really good idea to take control of your dreams while you're asleep.
OK, that's not funny but it's true. According to numerous authorities, learning to remain conscious that you're dreaming while you're still dreaming (a.k.a. lucid dreaming) is a powerful life skill you can develop by expending only 15 seconds every day.
More than any other life skill, you get a huge psychological benefit while investing only a tiny amount of time. It's probably the best ROI deal in the entire universe of psychology and self-help.

A Brief History of Lucid Dreaming

The earliest reference to lucid dreaming comes from Aristotle (b. 384 BC), a concept further developed by Galen of Pergamon (b. 129 CE), arguably the founder of most of Western medicine.
In Tibetan dream yoga (codified in the 10th century CE), initiates are trained to increase the frequency and intensity of lucid dreaming to help them more viscerally comprehend the illusory nature of physical reality--an important step toward enlightenment.
In more recent years, neuroscientists have discovered that dreaming in general improves memory, boosts creativity, and helps you plan your future, while lucid dreaming in particular prevents nightmares and increases the physical benefits of sleeping.

How to Have Lucid Dreams

Neuroscientists can induce lucid dreams in test subjects by zapping their brains with a weak electrical current for 30 seconds. Fortunately, there is a less dramatic (and surprisingly easy) DIY method: create a "what I dreamed" checklist.
It's long been known that keeping a "dream journal" increases the likelihood of lucid dreaming. However, just as most people don't have the time or energy to keep a waking journal for more than a few days, few will keep a dream journal long enough to spur the lucid dreaming.
The way around this problem is to create a list of all the common things you dream about and then check them off each morning the moment you wake up. When I've used this method, I leave a small space to note anything unusual, which seems to speed up the process.
Just as with the more laborious dream journal method, a checklist method helps break down the mental barriers between your waking mind and your brain during the rapid eye movement (REM) state when you're asleep and dreaming.

What You'll Get From Them

According to Tore Nielsen, a dream and nightmare researcher at the University of Montreal quoted in the National Geographic:
"The study might have clinical implications for treating conditions such as post-traumatic stress disorder and nightmares [and] being able to reflect upon yourself, to think about your past and plan your future."
While personal anecdotes have no scientific value, I can attest to the benefits of lucid dreaming, including:
  1. Ever since I was a child, I've had nightmares where I'm running away from a pursuing, faceless, nameless evil. When that happens now, I'm immediately aware that I'm dreaming and can either wake myself up or (and this is much more fun) turn around and attack the monster.
  2. Once I become aware that I'm dreaming, I can fly anywhere in the world in only a few seconds. I've even managed to reach escape velocity and seen the earth from outer space. Yes, it was just a dream ... but it was an awe-inspiring experience.
  3. I can also time travel. For example, I once had a long conversation with myself as a child, where I explained to my younger self that everything was going to turn out all right. I woke up feeling more at peace with myself and my life decisions.
Keeping a dream checklist takes about 15 seconds each morning, which isn't much of a time investment, considering the psychological benefits, not to mention the pure fun of, feeling exactly what it would be like to be a true evil-fighting superhero.