a man who takes pictures of kids and if you knock and run on his door he will follow you to wherever you lead him, he is like the terminator, he never gives up.

A phrase to describe someone who is cognitively degenerating. Synonym of "going off the deep end". Can have varying degrees of severity.

Reference to the song "Hey You" by Pink Floyd. The line "and the worms ate into his brain" makes no sense in an otherwise linear and literal narration throughout the lyrics.