Hi, I thought you may like this Mentalrobics exercise from Braingle.com:
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Concentration

The ability to concentrate is an important skill for a creative thinker. Without concentration you will be unable to dig past the trivial things on the surface and get to the interesting stuff the lies beneath the surface.

If you are having difficulty concentrating on a task, try pretending that you are not having trouble. Ask yourself what it would feel like if you were able to concentrate. How would you be sitting? What would you be thinking? Try to think back to a time when you were able to concentrate. How did you feel then? What is different from how you feel now? You can often trick yourself into concentrating if you think about what it would feel like to be doing it.
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For more mind exercises: http://www.braingle.com/mind/