15 Stupid Harry Potter Movie Mistakes You Probably Missed

The old adage goes: 'never work with animals or children' but the filmmakers behind the Harry Potter series had no choice but to cast three ten year olds as their leading men and lady. Daniel Radcliffe had some experience in the industry courtesy of his parents and a role in an adaptation of David Copperfield prior to the film series but Rupert Grint and Emma Watson came in knowing almost nothing about acting.

It isn't hugely apparent as the child actors immersed themselves in their roles and it was a refreshing change from some of the performances we had seen around the same time from younger actors - looking at you Jake Lloyd, as always.

Though the enthusiasm of the young actors gave a lot to the production value of the movies, there was an enormous issue with the youthful Emma Watson in that she is so similar to the character of Hermione that she enjoyed reading the script a bit too much.

Instead of learning her own lines and leaving it there, Watson took it upon herself to learn everyone else's including Daniel Radcliffe's, Rupert Grint's and even Robbie Coltrane's. Why is this an issue? Well, when the characters go to see Coltrane's Hagrid towards the end of The Philosopher's Stone, Watson can clearly be seen mouthing other character's lines.

This really should have been caught on the day of filming but maybe everyone was a little bit tired of Miss Know-It-All by this point.