Why did morrie become a teacher?

He chose teaching because he wished to live a meaningful life, give things to others, and devote himself to loving others.

"So many people walk around with a meaningless life. They seem half-asleep, even when they're busy doing things they think are important. This is because they're chasing the wrong things. The way you get meaning into your life is to devote yourself to loving others, devote yourself to your community around you, and devote yourself to creating something that gives you purpose and meaning." (43) --Morrie