Continuity mistake: The long cut on Peter's upper arm changes length, position and even its angle in quite a few shots when it is visible, in the Black Castle, followed by Peter and Wendy at the fairy dance and then after their own dance. (00:52:50 - 00:56:45)
Continuity mistake: Smee opens the door to Hook's stateroom, calls out, "Cap'n?" and from the exterior we see the large globe to the left. When Smee walks in, the globe is seen again from the other side, but the globe shows the exact same region and markings as when it was seen from the doorway. (00:27:35)
Continuity mistake: At the start, when Mrs. Darling plays the entry music for Wendy to tell her story, her hands lift up a little from the piano, but do not appear to move along the keyboard far enough for those notes to be played properly. (00:03:35)
Visible crew/equipment: Upon seeing the children when they've returned home, Mr. Darling hugs John and Michael. As John turns his head to look at Wendy clearly reflected in both lenses of his eyeglasses are four-square studio lighting. This occurs numerous times, with different types of lighting equipment visible in both John's and Mr. Darling's eyeglasses, as well as other's eyes throughout the film. (01:38:30)
Continuity mistake: In the bathtub Michael says, "Not fair," to Nana and his hair is combed differently, parted and much neater, in the next close-up. (00:02:45)
Continuity mistake: Peter stands at the window and says, "Come away to Neverland." In the close-ups as his hands grasp the curtains, hardly any of the white curtain is seen under his grip. Yet in the wide shots there is much white curtain seen in his hands. (00:22:30)
Continuity mistake: As Peter saves Wendy and scares away the mermaids his body position is very different in the wide shot between the two close-ups. (00:42:45)
Continuity mistake: When Peter floats up after John says, "You offend reason sir," the clothes wardrobe is seen behind Peter and there are three very large floral hat boxes sitting on top. Yet when Michael flies and lands on top of that wardrobe the floral boxes are arranged completely differently. (00:21:10 - 00:22:05)
Continuity mistake: When John wants to learn to fly, he flings back the covers on his bed. When he goes back on the bed to 'take off', the bed is made. (00:21:20)
Other mistake: When asking Wendy to be their mother, one of the twins asks, "Do you tell stories?" and Curly visibly mouths the word, "Stories," along with the twin, then goes on to say his own line, "Then you're perfect." (00:37:40)
Revealing mistake: Peter says, "There are mermaids! Indians! Pirates!" and then John shouts, "Woo hoo!" When he flies out through the nursery window his gown is visibly gathered at his back for the stunt. (00:22:45)
Continuity mistake: As Wendy approaches the Lost Boys to give them their medicine, in the close-up they surround Peter begging to be killed. In the next wide shot Tootles pulls one of the twins close and puts his arm around him, though in the next shot they are positioned as they were in the first close-up. Wendy's necklace changes within these shots as well. (00:39:15)
Continuity mistake: After Wendy admits to being Red Handed Jill, Peter holds his blade to Wendy's throat. In the first close-up Peter grasps the hilt so the sharp curved edge of the blade points towards the knuckles of his fingers. In the second close-up his hand grasps the hilt so that the sharp edge points towards the palm of his hand. (This has nothing to do with how his wrist is turned.) (01:05:30)
Continuity mistake: When Wendy walks the plank she stands at the edge and as the camera faces her the brilliant sunlight from behind her highlights the plank and casts a long bright shadow in front of her, contrary to the dark wood plank in the overhead shots. (01:20:10)
Continuity mistake: After the Lost Boys fire their arrows at the Wendy-bird, the position of the arrows on Tootle's back differs in the front shot and back shot as they watch the arrow hit Wendy. (00:33:35)
Revealing mistake: After having been kissed by Wendy, Peter flies towards Hook, who is tangled up in the rigging of the Jolly Roger and slashes the lines of the rigging thereby releasing Hook. As Peter swipes at the lines it is very apparent that he only touches a few of the pre-cut lines and the rest simply fall away. (01:31:50)
Continuity mistake: In the scene after Wendy kisses Peter, Peter comes back down from the sky and cuts the ropes binding Hook. Hook is still tangled in the ropes when Peter tosses him a sword, but in the next shot, Hook flies away from the ropes as if he wasn't ever tangled in them. There wasn't enough time in between shots for him to cut the ropes himself. (01:32:05)
Continuity mistake: When Wendy says, "But...this is yours.", Hook pulls her up by her arm onto her knees and her hair goes from being straight down over her right ear, to the next shot, when it is again tucked behind her ear as it appears throughout most of the film. (01:29:20)
Other mistake: When the Lost Boys spot the large white bird they argue about who gets the telescope. In the wide shot one of the twins slips and falls on the ground and looks directly at the camera with a puzzled look on his face. In the next close-up Tootles and especially Nibs start smirking, Nibs has to look down and away as Slightly says his lines and the other twin starts to look at the camera when the shot changes. (00:32:25)
Deliberate mistake: After Hook orders the crew into the rigging, Peter lands on deck holding Wendy. There is a close-up of Hook's face as he walks back down the stairs, then the next wide shot of Cookson, the very tall pirate up in the rigging, is flipped. (The shot before he points the gun.) (01:22:25)
Answer: It's not that you never age, it's that you never grow up, i.e. pass into puberty and become an adult.
Myridon