Questions about example sentences with, and the definition and usage of "Ossified"

A:

let’s imagine that we are talking about two people who have very firm opinions about something. Let’s call them Bill and Ted.

Bill has held the same opinion for so long that it has become ossified.
Ted is very certain about his opinion, and he is entrenched and ready to defend it.

The big difference is that Bill’s opinion has become fixed simply because he never bothered to change it. It has grown old like an old tree, and there is no use in trying to make an old tree grow in a different direction.

Ted, on the other hand, has been very active about defending his opinion. He has thought about it and decided that nobody is going to change his mind. Where Bill is passive, Ted is furiously active. He is willing to start an argument and defend his position. Bill just doesn’t care.