The Passage

It was possible, he understood, for a person's life to become just a long series of mistakes, and that the end, when it came, was just one more mistake in a chain of bad choices. The thing was, most of these mistakes were actually borrowed from other people. You took their bad ideas, and for whatever reason, made them your own.

As long as we remember a person, they're not really gone. Their thoughts, their feelings, their memories, they become a part of us.