Studies show a strong correlation between mental exercises and the slowing of brain related conditions like Alzheimer's. Not only does it appear to delay the onset but it seems it can counter act the speed at which the condition progresses. I've recently found a web site http://www.lumosity.com that specialises in "brain" games that work different aspect of your mind and lets you know how you are doing in each area. I'm totally addicted to it...ok not totally because I don't log in every day but I like it just the same.
Perhaps you don't want to flip the bill for such a site and in this day in age where so much of the world is screwed up, largely because corporations have gotten very good at gathering wealth, often circumventing the regulations were ever they can...anyway that's for another rant.
Even if you don't subscribe to the site. Give the free trial a go. Then move onto other things like sodoku or crosswords or word searches. Even if you don't like it at first. Especially if you don't like it at first. The best way to exercise you mind is to make it do things it doesn't normally do. Read more. Read things you normally would not. Ask questions. Ask questions about things you normally would not ask about. Find out about the world outside of your little world. Reflect on the world around you. If you don't know why there are riots in Greece then find out. If you think there are riots because they just spend money they don't have all the time then go and find the real reason. If you didn't know the American government handed prisoners over to Egypt to be tortured go find out. If you did know and agreed with it go read the Geneva Convention. If you think it is OK for the USA to do things to other countries that you think would be totally unacceptable for other countries to do to the USA go travel and see what the world is really like.
Don't let yourself think that to be educated is to be an "Elitist" and that it is better to be a common person then to try to constantly better yourself. We all have the ability to grow. We all have the capacity to get smarter. The same tool you are using here can be used to help you exercise your mind. And just like normal exercise you'll find the more you do it the better it feels to do it. The same rush you get from watching your favourite sport can be felt every time you realise you have learnt something new.
Don't get me wrong. It won't all be easy. You'll often find yourself frustrated. Growing up English was arguably my worst subject but over the years I've forced myself to use those types of skills. I'd like to think that today I'm half way decent at expressing ideas both verbally and via the written word. Now to just find out how I can learn not to go on rants on all the time.