Lynn Shelton’s “My Effortless Brilliance” is a study in the relationship between cocky, fussy, thoroughly-city-mouse author Eric (Sean Nelson) and his ex-best-friend, the tersely powerful journalist and wood-chopper Dylan (Basil Harris). Dylan, fed up with Eric’s self-involved antics, dumps him and disappears to live in a log cabin in the woods of Eastern Washington; two years later, Eric arrives (sporting a Prius, white sneakers, and a fear of spiders) to mend the friendship.