What do you think most influenced Morrie to become the person he became in the book Tuesdays with Morrie?
This is a personal question and your answer is going to be completely up to you, but I would submit that even before Morrie was stricken with Lou Gehrig's Disease, he was the type of person who tended to look on the bright side of things. At the opening of the book, Mitch Albom remembers him as:
...my favorite professor...He is a small man who takes small steps...when he smiles it is as if you just told him the first joke on Earth. (4)
Morrie already has something unique inside him. Even before he knows he is dying, he is touching the lives of his college students as a man who clearly sees the world through irregular eyes and an unusually positive spirit. The book does not chronicle anything before Morrie's journey toward death, so while it is impossible to pinpoint the exact why behind his wisdom, love, and grace, it is certainly clear that his advice comes from a lifetime of living what he believes, and not simply changing because of a disease he knows will take his life.
I might argue that Morrie must have had some very healthy and fulfilling relationships in his life. He is a man who sees the good in people, which, in my opinion, is very often passed on to children by a mother or a father. It is also clear (see the Fifth Tuesday) that Morrie has always had the support of a strong family. I think the strongest forces behind the character he develops are his personal relationships and experience which comes from his age.