OK, count the number of F in the following text:
+++++++++++++++++++++++++++
FINISHED FILES ARE THE RE-
SULT OF YEARS OF SCIENTIF-
IC STUDY COMBINED WITH THE
EXPERIENCE OF YEARS
+++++++++++++++++++++++++++
Done?
3?
Nope!
Count again, it’s 6
Explanation: Apparently, the brain cannot treat ‘OF’. If you counted 6 ‘F’ the first time, well you deserve a cookie
oh and check out this site
http://www.bbc.co.uk/science/humanbody/body/interactives/senseschallenge/senses.swf