You must not have retired grandparents...<p>here&#x27;s an old paper excerpt[1] about the &quot;use-it-or-lose-it&quot; nature of your brain:<p>&gt; The protective effects of an active cognitive lifestyle arise through multiple biological pathways, new research suggests. For some time researchers have been aware of a link between what we do with our brains and the long term risk for dementia. In general, those who are more mentally active or maintain an active cognitive lifestyle throughout their lives are at lower risk. New research throws some light on what may be happening at the biological level.<p>[1]: <a href="http:&#x2F;&#x2F;www.sciencedaily.com&#x2F;releases&#x2F;2012&#x2F;04&#x2F;120425094358.htm" rel="nofollow">http:&#x2F;&#x2F;www.sciencedaily.com&#x2F;releases&#x2F;2012&#x2F;04&#x2F;120425094358.ht...</a>