Look at the Coen brothers. All their minor characters are as interesting as their protagonists. If the smaller characters are well-written, the whole world of the film becomes enriched. It's not the size of the thing, but the detail.
“Perseverance is not a long race; it is many short races one after the other.”
“My writing is a combination of three elements. The first is travel: not travel like a tourist, but travel as exploration. The second is reading literature on the subject. The third is reflection.”