Adjective
intolerant - Refusing to allow others to do or believe things that you don't agree with.

When people try to dialog with others, and both are intolerant of each others' points of view, it often just degenerates into a shouting match, with neither side listening.
senile - Used to describe behavior, mental states, or conditions associated with aging, especially when a person becomes forgetful or confused.

The elderly man showed symptoms of becoming senile, like forgetting where he put his keys, but with support, he managed to live independently for a while.