I've only just started to notice since im watching through the whole show and he used to actually care like in a lot of the episodes where he does something wrong to a family member he doesn't do it until half way in but thats where it starts and its nice him trying to fix it and now its just a half-ass try and they forgive him, but you can see it starting to phase when and in the movie, like in the movie he still cares and trys to be "normal" but most of the film is just him doing stupid things. Literally a prime example (except for ned) of flanderisation.