Beginnings

The first half of Taxi Driver is about a guy trying to bed a girl way out of his league.  

The first 25 minutes of The Equalizer is about a hardware store worker trying to read a bunch of famous books.

The first 25 minutes of Falling Down is about two different guys - one trying to get through his last day on the job without incident and the other trying to make a phone call to his estranged wife.

I think this is what Tony Gilroy means when he says "start small."