For me, reading a book I haven't read before is more pleasurable than reading one I have. Since reading takes a large investment of time, I'd rather explore new territory
That is me I am afraid. More endorphins are released for me by a new book I am enjoying than by a previously read one. Music is often the opposite and Movies and Tv shows tend to put me to sleep so it can take me days to actually see one. I like video but unfortunately have been known to drift off even in a theatre.
I have zero pbooks due in part to getting an ereader and in part to space and the fact that I rarely reread them.
I have reread parts of some books accidentally and parts of some on purpose when a series was sold as one book at a reasonable price.
Still as I will not likely throw away ebooks, I may at some time reread a few others.
I envy those who get such pleasure from rereading.