What We Are and May Be

So, what does Ophelia mean when she says, "Lord, we know what we are, but know not what we may be," in lines 43 and 45 of Act 4, Scene 5? I interpret this line two different ways. When I first read the line, I interpreted it as saying that we may know what we are right now, in the present, but can never be sure what we will be in the future. This reminds me of the movie Reign Over Me, with Adam Sandler and Don Cheadle. In the movie, Adam Sandler loses his wife and three kids in the 9/11 terrorist attacks, and his life is turned upside down. Before he lost his family, he was a dentist as well as a happy father and husband, but after the traumatic event he becomes a hermit who pretends as if he never had a family. He knew what he was before 9/11, but had no idea what the future had in store for him. The second way I interpreted it was that, people may think they know what or who they are, but in reality they have no idea what they have become. I can think of many examples to illustrate my point. The first example that comes to mind is the movie Death Sentence, with Kevin Bacon, where his son is murdered by gang members while at a gas station. He then decides to get his own revenge after his son's killer is set free from jail. Kevin Bacon thought he was a grieving father, but in reality had turned into a killing machine.