"A lot of my friends, who were also retired, looked at me and said, 'What are you doing? Why? Why? You have the good life here. You're retired, you've got friends, you do a lot of volunteer work. You've got a dog, you've got grandchildren … So what's the deal?' " she said. "But they came to understand I needed more stimulation and meaning, and still had some juice in me to teach."