Peter's grown up after all but not really grown up, basically just grown older but still is the same emotional mess 'cause he can't let go of what happened with his mother not to mention open up about it.
This episode of "Reconstructing Grimm" shows the first Tag of the photoshoot for Peter Pan, with Chris MacGregor in the Titel role and Liz playing both Wendy and Tinkerbell.
This is for the novel. This is a remake of my many years old tribute to the same song. Just to make clear: The blurred gray bits are not Mrs. Darling but Peter's mother, and Hook does not really know about that trauma.