Harry Potter turns 20! Here are 8 facts to blow your mind
1. The character Snape was partly based on J.K Rowling's high school chemistry teacher, John Nettleship. He was mortified when he found out and said, 'I knew I was a strict teacher, but I didn't think I was that bad!'
2. Every wand featured in the film is unique and made on-set – no two wands are alike.
3. The oldest actor in the Harry Potter movies to play a student was Shirley Henderson who played Moaning Myrtle. She portrayed an 11 year old, even though she was actually 37.
4. J.K Rowling made Harry Potter wear glasses as a symbol of his vulnerability.
5. The number that Arthur Weasley enters in the phone booth to get to the Ministry of Magic with Harry is 6-2-4-4-2. The letters underneath those numbers on a standard telephone keypad spell out "magic."
6. In the movies the producers tried to give Daniel Radcliffe green eyes and Hermione buck teeth like in the books, but failed. Harry had an allergic reaction to contact lenses and Hermione couldn't speak properly with fake teeth.
7. The Hogwarts School motto is "Draco dormiens nunquam titillandus," which means "Never tickle a sleeping dragon."
8. The scar was applied to Daniel Radcliffe’s forehead over 2000 times during filming for the Harry Potter series.