Remain

Recently Angela and I watched the classic and genre shaping 1960 Hitchcock thriller Psycho. (warning movie spoilers ahead) In addition to embezzlement, intrigue, and murder, it is a movie about a son who is so obsessed with his mother and his relationship with her, he eventually takes on her persona and becomes her.
In what is known as “the farewell discourse” Jesus implores his disciples to remain in him and that he would remain in them. Later on, he prays that he and his disciples and all who would hear their message would become one, just as he and the Father are one. What is it that makes Norman Bates remaining in his mother psychotic, and Jesus’ message to remain in Him gospel?