Just like our bodies, our brain too, ages. However, since the symptoms of an ageing brain are not as prominent as that of the body (wrinkles, weight gain, hair fall etc), we tend to ignore the brain, which in fact is the most important organ of the body, along with the heart. However, exercising the brain is not that difficult, and if you have just hit 40 (or even 35) now is the best time to start exercising your brain, through these simple, but effective exercises.