This tends to be more in films than books, but what really bugs me is when they feel the need to open, usually with a news broadcast, that always goes something like "In 2034 Professor Whatever of the Wankydoodle Corporation invented Robot Ghost Dinosaurs (or whatever it may be) and our lives have never been the same since.........", or narration that says something like "Since the beginning of time, a secret underground war has been fought between *insert name of goodies* and *insert name of baddies* while humanity remained unaware........"
Suspend my disbelief by all means, but don't crucify it. This is one great thing about Philip K Dick - he would mention a technology, or show it, and just assume you knew what it was. I like that, crediting the reader with a bit of intelligence, and helps you stay "in world".