But we do not know exactly what we should be doing, for how long and with whom (social activity may be better than doing the crossword on your own, for example) to keep our brains in good shape.

In the absence of scientific certainties we can only say that keeping up all levels of mental stimulus certainly won't harm and might just help our brains! Commit to trying new experiences, learning and playing and you'll enhance your mood, too. Studies have shown that people who live longer are content with their life and involved in their communities.

As for coping with memory deficits, memory can be trained to some extent and we can learn strategies to support our forgetful minds, whether it's making lists or using imagery to help. Enhancing other skills, such as concentration, will also help.

As we get older, our minds are ever bigger warehouses of thoughts, feelings, memories, worries and other distractions that can get in the way of action. Our older brains, however, are also an immense storehouse of experience that we can draw on - and share.