Don't read the book then.
Matheson did a fantastic job with that relationship, in my opinion.
The whole title is more understandable and more apt in my opinion in the book as opposed to the film. I had such hope for it until I heard who would star in it and then saw the poster. "The Last Man on Earth" (1964) staring the quite brilliant Vincent Price was a far, far, better movie adaptation, while still being grossly inaccurate to the book.