I started reading history hoping to learn how to avoid the mistakes of the past, and instead came to the conclusion that history inexorably repeats itself, over a cycle just long enough for the current generation to forget the last event. (I'm trying to indicate similar kinds of mistakes in judgment, the details are always different of course.)
I think people just say this to make themselves feel better about the dire situation we're in. Whatever works, but it's not quite true in my opinion. The dinosaurs weren't just a "blip" to us.