Well, self-explanatory. The title of the film and the novel on which it's based describes the main character, Benjamin Braddock, who is a freshly minted college graduate. But that's all he is; he hasn't done anything else yet. He's not the future engineer, or the budding artist. About all you can say about him is that he's a graduate.
Ben has no point of orientation in the world, and can't figure out where to go or what to do. Naturally, this feels alienating. It's not until he meets Elaine and sees some kind of future out there that he starts to break out of his inertia. By the time the movie ends, he's successfully won Elaine over, but the future before him, and what he's actually going to do remains an open question. The movie begins and when it ends; Ben's still a graduate and not anything else.