Book excerpt: Do you forget things easily? Are you worried that you're losing your mental edge? Don't be! Keep Your Brain Sharp will prove that, in fact, your mature brain is bigger and better than ever, and it will give you hundreds of diverting puzzles, games, tests and exercises to keep it that way. It explodes the myths about old age and mental decline, explains why you get better when you get older and gives you a set of great mental workouts in a brain-boosting bible ideal for you if you think your best intellectual achievements may well lie ahead. NOT GOT MUCH TIME? One, five and ten-minute introductions to key principles to get you started. AUTHOR INSIGHTS Lots of instant help with common problems and quick tips for success, based on the authors' many years of experience. TEST YOURSELF Tests in the book and online to keep track of your progress. EXTEND YOUR KNOWLEDGE Extra online articles at www.teachyourself.com to give you a richer understanding of how to keep your brain sharp. FIVE THINGS TO REMEMBER Quick refreshers to help you remember the key facts. TRY THIS Innovative exercises illustrate what you've learnt and how to use it.