In the text above there are actually 10 F’s! Generally, all people undercount the number of F’s because they fail to notice the letter ‘f’ in the word ‘of’. The words like ‘of’ are unconsciously processed by our brain because they aren’t considered important.
Those who counted,
2-4 : Ordinary (55% people are coming under this category)
5-8 : Extra ordinary (45% people)
8-10: Genius (10 % people)
