I'd like to thank TKC interview guest Sara Nelson for her sentiment that it is OK to not finish a book.
Why? I could maybe say "life is too short" and leave it at that. :-)
But: why not? I think the feeling that one *must* finish what one starts is a misplaced idea of ethics, possibly ingrained in us when growing up. It is good in many places, like the workplace. But it can be taken too far.
I start a lot more books than I finish. For fiction, I can only really tell if I like a book by reading some of it. And if I don't, I may just waste my time by continuing. For non-fiction the same applies, plus that I often feel I've gotten out of it most of what I can without finishing it. Many writers noodle around much more than needed.
And most importantly, the time used to read a book I no longer care for is directly taken from time reading a book which I like better, or which teaches me more.