How did Mitch change by the end of the book?

In the book "Tuesdays with Morrie" Mitch evolves as a person. Mitch had promised to visit Morrie but doesn't come back for years. As Mitch begins regular visits, he sees in Morrie a humble friendship, a communion of sorts. He watches Morrie's body disintegrate yet marvels at his humour and dignity through the indignity of disease. By the end of the book Mitch appreciates life much more. He values the simple things and ceases to fret about the complex things that often can't be changed. Mitch decides to pursue his passions because really, life is too short to do otherwise.