Continuity mistake: When Belle jumps off the horse-drawn carriage and goes into the bookshop, the bookshop window consists of four glass panels alligned in vertical columns. However when Belle leaves the bookshop, the window has suddenly changed to consisting of three glass panels alligned in vertical columns. (00:04:25)
Continuity mistake: When Belle lets Mrs. Potts in, she then walks backwards into the wardrobe, and you can clearly see the wall from the bed to the corner is made up of three large purple wall panels. However in a later shot, when the wardrobe opens her doors and the moths flutter out, the wall is now made up of four purple panels. The design on the panels differs too. (00:30:20 - 00:31:10)
Continuity mistake: The amount of snow on the stairs of Belle's house constantly changes in the scene where the villagers try to take away her father.
Continuity mistake: The eagle in the bar constantly changes size throughout the "Gaston" song.
Continuity mistake: When Lumiere and Cogsworth are trying to persuade Belle not to go up the stairs to the West Wing, they start suggesting other places to go. When Lumiere says "..the gardens, or the library.." you can see that Cogsworth, Lumiere and Belle are all standing on the same step. Then when it cuts, Belle is standing on the step below Lumiere and Cogsworth. (00:42:05)
Continuity mistake: After the wolf attack, Belle has a bowl of hot water. In the shot where she raises the white cloth and wrings it out, there is a large beige pillar directly behind her. When it cuts to a wideshot of the whole room, the pillar has vanished. (00:46:55)
Continuity mistake: In 'Be Our Guest', Cogsworth is in the blueberry pie, and has blueberry and pastry over him, yet in the next closeup it's gone. (00:39:10)
Continuity mistake: The doors to the fireplace are ovalish with triangular tops when Cogsworth says "No tea, no tea." When the Beast bursts in, they are rectangular.
Continuity mistake: Gaston wears a quiver in the scenes where he is after the Beast, and the brown quiver strap runs across his body over his red shirt. After Gaston stabs the Beast with his knife, the brown strap and quiver is still on. However it then cuts, and as he starts to fall, the brown strap of the quiver has gone. Then in the next shot the strap is back on, over his red shirt. (01:16:15)
Continuity mistake: At all times, the enchanted rose is on a smooth marble table, except for when the Beast roars with pain after Gaston shoots him with an arrow. In this shot the table is wooden.
Continuity mistake: Just after the Beast tears the painting, look carefully out the window and you'll see a carving of a person with his mouth open on the balcony. Then when the shot zooms out of the castle, this carving is gone.
Continuity mistake: At the start of the song "Kill the Beast", the mirror keeps coming closer and further away from the buckle on Gaston's belt.
Continuity mistake: Belle takes a blue book from the library, but in the shot where Gaston sings "I'm making plans to woo and marry Belle" the book is now brown.
Continuity mistake: During 'Belle', we see Belle sit beside the fountain in an overhead shot, and there is a woman washing a white sheet in the water, with nothing beside her. Then it cuts to a closer view of Belle and you can now see a blue basket of white sheets on the floor beside the washing woman. (00:05:00)
Continuity mistake: When Belle is reading her book inside, there is a black teapot over a plate on one of the shelves. Moments later, the plate is to the teapot's side.
Continuity mistake: When Maurice enters the castle, the front doors have four planks each. For the rest of the film, they have five planks each.
Continuity mistake: During the song "Gaston", in the shot where Gaston leaps into the wrestling match, the eagle and warthog head decorations disappear from the wall. (00:28:01)
Continuity mistake: After the Beast is stabbed, and is on the floor dying, Belle is at his side comforting him. In one shot her hand is stroking the left side of his face. It cuts and suddenly her hand is on the right side of his face. Then a few shots later, she puts her left hand on the right side of his face, but when the shot changes her hand is back to her side. (01:16:40)
Continuity mistake: The width of the grey rings on Maurice's lantern changes in the scene where he is lost in the forest with Phillipe.
Answer: In the prologue, it states that the Beast must find true love by his 21st birthday, and that he had been cursed for ten years, so since his relationship with Belle takes place as the deadline approaches, he must have been 10 when he was cursed.