Quote 1
"Mitch, I don't allow myself any more self-pity than that. A little each morning, a few tears, and that's all." (9.13)
Morrie has to make the choice to be positive every single day. It's not easy. He wants to give in and be miserable every morning, but after allowing himself to be sad for a little while, picks himself up again and resolves to be happy.
Quote 2
"Whenever people ask me about having children or not having children, I never tell them what to do," Morrie said now, looking at a photo of his oldest son. "I simply say, 'There is no experience like having children,' That's all. There's no substitute for it." (14.19)
Morrie says something important here: You can't make decisions for other people. He knows that the important things in life have to be decided on your own, so all that you can do is tell someone your own experience of having made a certain decision.
Quote 3
"[But by throwing yourself into these emotions,] you experience them fully and completely. You know what pain is. You know what love is. You know what grief is. And only then can you say, 'All right. I have experienced that emotion. I recognize that emotion. Now I need to detach from that emotion for a moment.'" (15.35)
Being self-aware is key to making choices. Morrie says that he's able to make choices about the way that he's going to feel, and that once he looks honestly at himself and accepts what he's going through, he's able to judge which decision will be the best for him.