a teacher worth respecting

During high school, I met a teacher who I could respect.
Besides doing his regular job, he did after school classes.
You might think that this is nothing special,
but the number of classes he did and what he did for the class was incredible.
He gave classes almost everyday after school. There were no classes only when he had to go on a buisness trip. Otherwise, he did classes on weekends too.
He even did some on holidays like the New Years eve. He also paid for the fees it took to hold these classes.
When a student asked him why he did so much for us, he said that it was nothing special, and that he thought of this as a natural thing for teachers to do.
From this, I came to think that people who have pride in their job does not only do what is least necesary, but does what he or she thinks is necesary.