Trick on eyes
I went to watch an I-Max documentary in the Reuben H. Fleet Science Centre in Balboa Park thanks to Harriet. It was my second time watching I-Max but couldn't remember my first experience. Think it was in Singapore years back.
But anyway, it was OK but got a little bit dizzy while watching with the screen so big surrounding you. After that, we walked around the science educational exhibit that I must say really interesting. Both of us got tricked by our very own eyes. Try reading the sentence below just once and count the number of "f" (only once and do not go back to check again):
The finished files are the result of years of scientific study combined with the experience of years.
Answers are at below, scroll down after finishing and no peeping!
Answer: 6