Should I pay more attention to footnotes?

I got the book about a week ago and I'm about 100 pages in. I really like it but alot of the footnotes seem kinda unnecessary. I get there are some that provide insight into the book and all but there are so many just citing books that don't even exist. Am I missing something? Is it just to add more authenticity because it kinda gets tedious to repeatedly think theres an important peice of information and its just a citation for a made up book. Again, I know there's important info in the footnotes but I feel like I'm missing something with all these useless ones