When I was a teenager, my parents and teachers would routinely tell me that I was not living up to my potential. I stood there, receiving a lecture and trying not to roll my eyes, until something clicked and their advice was well-taken. I had forgotten about those earnest adults until I watched Boyhood, the most ambitious film to date from Richard Linklater. Its scope is unlike anything we’ve seen in the movies before, and the premise creates an opportunity to tell a familiar coming-of-age story in an organic, sensitive way. Linklater uses broad strokes, with plenty of pop culture references that shift from nostalgic to modern. The trouble is that sometimes the story and hero are too broad, as if Linklater worries a defined personality would ruin the film’s universal appeal.