Albert Einstein once said, "Intellectual growth should commence at birth and cease only at death." And these days, experts on aging agree. Studies continue to show that lifelong learning is the key to keeping our minds sharp and our brains strong, an important contributor to wellness overall, as we grow older. "Cognitive decline is not a normal function of aging," insists Andrew J. Carle, executive in residence and the founding director of the program in senior housing administration at George Mason University in Fairfax, Va. "The brain doesn't have to be in decline. You can keep it strong; you can exercise your brain."