Men of science, even the women, used to believe that starting about age 30, our brain cells begin to die off, never to return. Bummer.

Our ability to remember, to learn, to perform challenging mental tasks, such as locating our car key or recalling the title of the George Clooney movie we saw last week, all diminish as we age, we were told, and there's nothing we can do about it except surrender to a steady and depressing cognitive decline.

Don't rush through that last sentence. Slow down — one of the secrets of healthy aging — and take it on board: Your aging brain is highly adaptable and deliciously dynamic, and thanks to the discovery of neuroplasticity and neurogenesis, we now know our brains are perfectly capable of growing, changing and improving as we get older. Move over, Baby Einstein.

In their fascinating, fun-to-read new book, Gelb and Howell inspire us to retrain our brains for lifelong success. "People of average intelligence can, with appropriate training," they explain, "raise their IQ, enhance their memory and sharpen their intelligence."

And that's just people of average intelligence. Imagine what a smarty pants like YOU can do if you're willing to follow their expert advice. Here then are a few highlights from "Brain Power," along with one disclaimer: Best-Selling author Michael Gelb (www.michaelgelb.com) is a friend of mine. I commented on an early version of the book and made it into the acknowledgements, though he did spell my name wrong. No problem. Forgiveness, it turns out, is a key strategy for building a healthier, happier brain:

ACCUMULATED STRESS, a mind-boggling amount of research shows, is the greatest cause of age-related mental and physical decline. The good news is you can counteract it. Meditation works wonders. So does regular exercise. And so does brain-wave training. It's called Brain Synch in this book, a technology breakthrough pioneered by Kelly "the Brain Whisperer" Howell. It uses harmonic layers of precisely tuned sound waves (called "binaural beat frequencies," delivered via headphones) to rapidly and effortlessly shift your brain into patterns designed to dissolve stress, balance the right and left sides of your brain, and create a state of deep calm.