That story is a kind of coming-of-age tale, in which McCartney — only 15 when he met John Lennon — tries to find his footing without the band and winds up creating a new one instead. Along the way we learn about his relationship with Linda and their children, his creative process, his quarrels and reconciliation with Lennon, and certain escapades involving marijuana. There’s a lot packed in here, though there’s a lot left out, too; this movie is McCartney’s side of every story.