why did the grinch hate christmas

The Grinch hated Christmas because he was a bitter, mean-spirited creature who resented the joy and goodwill that Christmas brought to others. The Grinch's heart was so filled with bitterness that he couldn't stand to see others happy, and he believed that Christmas was just a superficial celebration that only emphasized the inequality between rich and poor. However, after witnessing the true spirit of Christmas through the eyes of Cindy Lou Who, the Grinch's heart eventually grows three sizes, and he finally understands the true meaning of Christmas.