Instead, grab your listeners attention by giving them the gem of the story, THEN go back and start at the beginning.
For example, for Twins, the pitch (and it's said that it was the shortest pitch in history, since the writers got the money as soon as the words left their mouths) was: ‘Danny de Vito and Arnold Schwartnegger are twins’.
It wasn’t: ‘Well. Arnold Schwarzenegger is living on this island where he’s lived all his life because he was part of an experiment to produce a kind of superman by combining the sperm of many high achieving men across many professions, and the scientist who created him is there as well and ...yadda yadda ...yawn.'
See what I mean? Whack 'em with your solid gold idea, then tell the story.