The Grinch’s heart shrank after the death of his mother.
After his mother died, his father grew angry and bitter. He then created the Grinch’s Oath and taught it to his son. The face in the mirror is Grinch Sr. (He says “That’s my boy!” of the Grinch.), but he appears in the mirror because the Grinch has metaphorically become his father.The Grinch in the mirror is a representation of the Grinch's father.
Just as the Grinch saw his mother in the puddle of teardrops, he sees his father in the mirror. While his mother was a good person, the Grinch ended up emulating his horrible father.- He does say “that’s my boy.” To the Grinch.
The Grinch actually IS sick in the head
His reflection bullies him and alters his behavior? Check. He sees a hallucination of his mother in a puddle? Check. Has violent mood swings and an aversion to loud noise? Check and check. It could be a number of issues but the likeliest diagnosis is schizophrenia.This is not the real Cat in the Hat, but Little Cat Z.
If Whoville is on a dust speck and the Grinch lives north of Whoville, then obviously he's microscopic. The real Cat in the Hat keeps Little Cat A under his hat, who is like the Cat himself but small enough to fit under his hat. Then Little Cat A keeps Little Cat B under his hat, then Little Cats C, D, E, and so on. This would mean that Little Cat Z, the last one, is tiny enough to be the same height as the Grinch. Which begs the question: why didn't he just use his Voom on the Grinch?- Maybe it's only for cleaning up messes, not reforming people.
