Got this from claire, tis quite good...

Quick Eye Test
Count the number of F's in the following text: FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS


Managed it? Scroll down only after you have counted them!







OK?


How many?







Three?









Wrong, there are six - no joke!



Read again!




FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS



The reasoning is further down...

The brain cannot process the word "OF".


Incredible or what?

Anyone who counts all six F's on the first go is a genius Three is normal.