How quickly do you form your first impression of a book? If that first impression is not favorable, how much time do you allow before giving up for good?
I'm a bit embarrassed to say I tend to give books that haven't impressed me initially more benefit of the doubt than I sometimes do people. Perhaps I trust my instincts about people more than I do my instincts about books. It's also possible I stick with some books that don't start strong because I've been sucker-punched by books that have great first sentences, paragraphs, or pages but subsequently fall short of that initial promise.
At present, for me, there's also the "apple polisher" syndrome. That is, I'm giving books assigned by my favorite book club moderator a lot of latitude. I hang in there with those even when my third or fourth impression is still not great. Mostly, I've been pleased I persisted because when I later hear the discussion, my appreciation for what I read deepens even if the book in question won't ever be on my list of favorites. But because I trust this moderator's discernment, I'm tenacious. The moderator also made a favorable first impression on me. Maybe that's no coincidence?