I spoke last evening to a group of mystery lovers, some of whom might have exchanged places with me and done a fine job. It's scary to face an audience of experts, and the depth of knowledge some readers have in specific sub-genres or about specific authors often amazes me.
For most of my life I was a grazer of mysteries, reading whatever was available and paying little attention to who wrote what. I knew I liked certain authors, of course, but didn't give much thought to why. When I became a writer, I started actually meeting some of the people whose work I admire, along with a host of writers I'd never heard of. Or had I? Often I found that once an author spoke a bit about his/her protagonist, I'd think, "Oh, right. I read a few of those books." I just hadn't bothered to commit anything to memory. Reading is entertainment, and there are no quizzes later.
I pay much better attention now, but all those past books huddle dimly in my memory. I may recognize the sleuth, I may hear a title and know I read that book once upon a time. But I was a bit of a glutton, feeding on a book and then moving on, often retaining little of it. Now I make an effort to categorize and examine, comparing each book to others in the genre, and of course, to my own.
When the topic is mystery, I can hold my own in most discussions, but I still consider reading to be entertainment. I'm aware that there are many who are better than I am at recalling all the details, to whom mystery is a Serious Thing. When they show up in my audiences, I'm always glad to let them educate me.