I have been in book groups for 50 years. We discuss the aims of the author, what the book tells us about the human experience, how it illuminattes cultures different from ours, and what people believed and believe in various times and places in history.
We also gain knowledge and wisdom which are two quite different entities. Enjoying a great book is a pleasure that we can share with others in a group. It's wonderful to glean insights from others who view a novel in a different way than I do because their experiences and cultures vary from mine.
I discussed All the Beautiful Things That Heaven Bears with an Ethiopian young man and was very impressed to learn his view of the novel which, naturally was very different from my own.
I also discussed Remembrance of Things Past with a French woman who told us how the English translation of the book differed from the original French version. I could not have learned this knowledge unless I was in the group.
More cerebral electricity takes place in a good group. The trick is to find members who care passionately about reading.
Of the many groups I've been in only 2 have really satisfied my soul. Sadly, one of the members who was the greatest contributor to the group I love the most died last week.
I am so bereft.

Sorry for your loss.

Sorry to hear that Macduff.