Linklater works best when he lets things be, and it's more difficult than it sounds to create a movie (a construct of an idea or an actualization of someone's vision) that achieves this natural feel. Before, movies have achieved the illusion of time passing by using makeup, cgi, or hiring different actors (on a related note, Brad Pitt's child in Tree of Life is a dead ringer for his fictional father). Boyhood actually follows the same actor so that in a 3-hour movie, we literally see young Mason (inhabited by Ellar Coltrane) grow before our eyes.
The idea itself is wholly original, ingenious, and is enough to make this movie a uniquely appreciative experience. Boyhood takes us not only through Mason and his family's life, but also through the landscape of the culture behind him. It's interesting to note exactly what music, political backdrop, or cultural ramifications (or en vogue haircuts) can immediately pinpoint where exactly Mason is in the decade. Although these conversations and settings inject points of humor and recognition, it also unfortunately and rather inevitably serves as the most forced part of the movie, making us both aware of what the year is and also that there's a director present.
Boyhood has a terrific cast other than the titular Mason. Mason's sister is actually played by Linklater's daughter, Lorelai Linklater. We see also a Linklater familiar in Ethan Hawke, who seems to have a great working relationship with him. The movie strives to be untidy and doesn't wrap things up neatly. Some events we can see coming long before the people in them, and others take us by surprise. Despite the lack of a real plot line, the movie is engrossing and there's a feeling of privilege to witness these segments of life in such an intimate manner.
If nothing else, Linklater and his work are to be watched. He's consistently creating movies that are individual from anything else in his field. Linklater has a patience and appreciation for those naturalities of life that can't necessarily be fabricated, and Boyhood encapsulates the growing pains and wonders of someone fitting into his skin and the fragile strength of all the relationships that foster someone truly coming into his own.