I often write code to solutions on paper or white board just to see if I can do it that way. I don't get it right every time, probably 50% of the time. I also try different complexity levels.

My reasoning for this is varied from most peoples. I love to teach. Right now I just answer question among my peers like at this site or at my workplace, however, I'd like to be a consultant some day, similar to what merlyn does.

I practice on the white board so I can correctly answer question about code on the fly, similar to your problem.

I wouldn't question my knowledge of the subject, I would try the most simplified solution that I'm >= 90% sure will work.

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Casey
   I am a superhero.