Though the Grinch isn't the most good-looking guy out there (hey, to each his own), he does manage to become a more attractive character over the course of the book. The Grinch starts out as a vindictive, Christmas-hating jerk of all trades. But by the end of How the Grinch Stole Christmas! he has reached an epiphany that Christmas isn't all about foil-wrapped gifts and giant bedazzled trees; it's about something more important than that. When he sees the Whos join hands and start to sing, he cannot help but undergo some real changes, including the literal growth of his heart.
Q: If he starts off with a heart that's two sizes too small at the beginning, and it grows three full sizes later, then how big is the Grinch's heart?
A: Um, that's a question for your math teacher, kiddo. Mama doesn't multiply.
Q: Why's he so stinkin' mad at the beginning? Who hates Christmas?
A: Maybe the Grinch is lonely. You know, it must get awfully cold and quiet up there in that cave.
Q: Why does hearing singing make him change his mind? Hasn't he been hearing those Whos sing all along?
A: You know what? You're right. He has been hearing those Whos sing all along. So that raises the question: what's different this time? Maybe it's because they're singing sans presents.