Knowing what the author knows or what they have gone throw can give you a better understanding of their points and liking's.
Explanation:
The other can be opinionated to some things and seeing their history can show you a pattern in the way they think. Or you can see if they have been scared by something and see why they feel for another.
to show the other part or other side like pros and cons there can be the pro of the argument and the cons the cons can show why/when/where the bad parts of the topic/theme is
