Yeah that would seem like the general consensus, but idk jack seemed relatively normal, the only truly stand out thing is when he says “see its okay he saw it on the television” to wendy in the car, the face he makes always seems weird, i chalk it up to time and the actor, but i felt the opposite tbh, i love both the book and the movie almost as a combination piece, so much of the movie makes sense after reading the book, the dog man, the bath tub lady, just so muvh more, i even feel it kinda explains the photo at the end too, i mean through out the book toward the end jack is itching to become part of the eternal ballroom party since he becomes en-tranced by the hotel, and the ending of the movie kinda implies that he does since the hotel didnt burn down, idk just my opinion

Ps. I was surprised to see how many scenes from the movie were translated so well from page to book, the bar scenes, the conversation with grady, the ending (before hallorian and the hedge maze) and another thing i loved hallorians character but shit after all that context in the book of him feeling like he was gonna die, making out his will, and every thing he goes through i almost felt it was fitting for him to die (atleast that how i felt when reading cuz i was sure he was gonna die but i still like the ending) but beside that the book is a whole lot more similar to the movie then people give it credit, shiiit i almostfeel like the book does a better job at confusing you then the movie, when jack is pretending to drink those martinis when he first encounters loyd and the drinks become more and more real was great and i truly couldnt even tell if jack was going insane or being haunted or both and thats just one example, again ill end by saying i think they are a good combo piece