He has no idea how to interact normally with other human beings. So he came up with this scripted narrative about something he actually enjoys and spouts it off to anyone he can in an attempt to seem "normal" in their eyes. He's trying to act casual and get his potential victims to relax, but he can't hide his weirdness and the awkward stilted monologue sets off alarm bells, despite his best efforts.

The boy just ain't right.