Here's a great post by SharpBrains that simplifies how to increase your mental edge.  Because a healthy brain is imperative to a productive and truly enjoyable life, you'll want to follow these four steps to keep you on the right track.   

1. Physical Exercise
... If you can only do one thing, do something cardiovascular, meaning something that gets your heart beating faster.

2. Mental Exercise
... If you can only do one thing, learn something new every day.

3. Good Nutrition
... If you can only do one thing, eat more vegetables, particularly green leafy ones.

4. Stress Management
...If you can only do one thing, set aside 5-10 minutes to just breathe deeply and recharge.

I'd like to sum this up by stressing point #2, this is highly underrated in our computerized, televisionized, and utterly cognitively deprived society.  You can be different, get out of your comfort zone and learn something new today; read for knowledge, perform a new workout, challenge your body and challenge your mind...

Go for it!