Continuity mistake: When Chip rides Maurices woodcutter towards the cellar, between shots the barn door goes from open to closed. (01:11:55)
Continuity mistake: When the household items fight the mob, six beermugs fling tomatoes at a man. It cuts and there are suddenly just five beermugs. (01:12:15)
Continuity mistake: When Gaston's mob comes and the dresser jumps on someone, she starts to jump down stomach first, but the next shot of her, she's feet first. (01:12:25)
Continuity mistake: When Le Fou and two other men chase the dog-like footrest, Le Fou has a pitchfork and the men have an axe and a sword. However when they bust through the kitchen doors, the sword has turned to a club. (01:13:10)
Continuity mistake: When Le Fou is chasing the dog-like footrest he is missing one shoe, which the dog has, but when Le Fou and the gang burst through the kitchen door, he has the shoe back. Then when the knives scare them away, it's missing again. (01:13:10)
Continuity mistake: Near the end, as the objects arrive and are watching as Belle helps Beast lie down, the rose stem is shaped as a question mark. A few seconds later, viewed from the same direction, when the last petal falls the rose stem is now shaped as a reversed question mark. (01:14:40)
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)
Factual error: After Gaston stabs the Beast in the fight sequence, there is no blood shown on the knife. [This is a longstanding Disney animation tradition. The House of Mouse seems to believe that onscreen violence is less traumatic if all evidence of it disappears quickly. Thus, you rarely see blood and when it IS seen it's usually minor, even if the wound isn't minor.] (01:16:15)
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)
Deliberate mistake: At the end of the film, Gaston shoots the Beast with an arrow and pushes the Beast out the window. When the Beast lands on the edge of the castle rooftop, the arrow has disappeared. Even if part of the arrow has broken off, a piece of it would still be in his back. [This, like many other incidents in the film, is a longtime Disney animated tradition. The company seems to believe that violence is less unpleasant if all evidence of it disappears quickly. This is why so many cuts seem to disappear or become less serious. The arrow vanishing is just another example.] (01:16:55)
Continuity mistake: When the Beast briefly dies at the end of the film, before being turned human, Belle cries and lays down on his chest, with her head resting on his red cape and her hand clutching it. However when it cuts to a closeup, Belle's head is suddenly resting further down, on his white shirt, and she is clutching the shirt now too instead of the cape. (01:17:35)
Continuity mistake: At the very end, when all the objects change back into humans, the position of the roses on the walls in the background changes between shots. (01:23:25)
Continuity mistake: When the Bimbettes sing "Oh, he's so cute!", the hand-pump lever is lowered, only to reappear raised one frame later.
Continuity mistake: After leaving the Bookseller store, in an overhead shot Belle passes a shop just as a woman is pouring water towards the downspout, and in the next shot the shop suddenly has a large hanging pipe sign with a table under the window, the green shutters have vanished on the right window, the half-timber wall pattern and wood trim have changed, etc.
Continuity mistake: At the end of the song "Belle", there's an overhead shot in which you can tell that there is no mud on the street in front of Belle. Then a few seconds later, there is a big puddle of mud, and Gaston throws her book into it.
Continuity mistake: When Gaston has his feet on the table, the amount of mud on the book and tablecloth changes between shots.
Continuity mistake: When Gaston proposes marriage to Belle, there is a thick pink cushion on his chair. But when Gaston sits on it and puts his feet on the table, the cushion is much thinner, and it is now red.
Continuity mistake: When Belle opens the door to the kitchen there is no shelf on the wall beside the door, but in following shots one has suddenly appeared with items on it and more things hanging underneath, which changes when Cogsworth lands in the bowl.
Continuity mistake: When Maurice is tossed out of the tavern we get a nice view of the front with its large hanging sign, but after Gaston whispers his plan to LeFou once again we see the front, which is quite different. The sign is gone, and now there are horns hanging on the awning, etc.
Continuity mistake: When Belle is reading her book before Gaston walks in to propose, the bellows hangs from a hook on the fireplace stones under the mantle, but when Gaston is talking to Belle the bellows now hangs directly from the wood mantle, though it's back to the original way when Gaston knocks over the rocking chair.
Answer: The Rose started wilting at The Beast's 21st birthday and could have presumably started wilting years before the first time we saw a petal fall off. Given the fact that Lumiere stated that they were living with the curse for 10 years, prince Adam could be 23-24 years old at the time of the original movie,13-14 at the time of the curse, and the Rose could have been wilting for two to three years. This is my best guess given the approximate age of Prince Adam in the ripped up portrait before he was the Beast.