I think it depends on which method the person tries. I also think that this is more of a perspective puzzle but doesn't fully sum up one's genius. There are a few ways one may look at this text, like one may read the text finding that their brain detects sound better (when reading outloud maybe) and could detect the F's better that way (or are verbal thinkers). Or they may be a visual thinker, and could catch visual things better. Most aspies are visual thinkers. It's only a guess. Brain puzzles can be very interesting; puzzles in general are fun on your spare time, and what's more they stretch your thinking and you could probably think broader (or more open) after doing more puzzles.
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I'm 24 years old and live in WA State. I was diagnosed with Asperger's at 9. I received a BS in Psychology in 2011 and I intend to help people with Autistic Spectrum Disorders, either through research, application, or both. On the ?Pursuit of Aspieness?.