Dramatic Irony is a situation in a drama wherein the characters in the play cannot grasp what's happening, but the audience can already understand what is going to happen and understood what has happened. So the answer is, Audience knows something the characters don't know.
I think people succeed when they set a goal and challenge themselves to reach that goal. You will most likely have a million small successes that only you know about before the world sees any of your success. You have to be happy with not achieving your goal the first time you try and you have to dream. If your dream doesn’t scare you then you’re not dreaming big enough.