A novel's Introduction gives us some insight into the author's life or the circumstances surrounding the publication of the book. I enjoy reading about that sort of thing. I think it can help to really enhance my understanding and appreciation of a book and I like learning something new about my favourite authors.
What I don't understand is why are the Introductions to so many novels filled with spoilers?
If you're going to give away key aspects of the plot surely it would be a good idea to warn the reader beforehand or at least move the Introduction to the back pages of the book.
I know that this should come as no surprise to me. I should resist the temptation to read the Introduction until after I've read the rest of the book. It just irritates me.
The last Introduction I read welcomed new readers to the novel only to tell them a few sentences later that our main character was going to commit a double murder and then off himself in the final pages!
I suppose you could argue that it's about enjoying the journey and that if you're really engaging with the characters and the story then you can almost predict what is going to happen. But I still don't understand why the publishers or the authors would allow the plot to be given away before the reader has even begun the novel.
Does anyone know why they do this?