Earlier this year, Noah Baumbach released While We’re Young, a movie about a middle-aged couple rediscovering their joie de vivre by befriending some hip 20-somethings. Now comes Baumbach’s second film of the year, Mistress America, a movie about a college freshman discovering her joie de vivre by befriending a hip 20-something. Hip 20-somethings — so hot this year (and every year).