I watch my photo archive and I realize that my memory does not recall a lot of things. Even photos from couple of years back seems like pictures of events that happened to someone else. I remember when I took that picture, however it's like I see this for the first time.
The memory has a strange way to forget things. I still can't believe that my boy was that small. I know rationally, however I cannot recall the perception of him being that small. Pictures are not only anchors for memories, sometimes they are the only memories.
Our children are the first generation that can have, over years, a history in images of their entire life. Of course, we also have some pictures from childhood, but they are too few to create an image of continuity. Most of our childhood pictures are black&while and in studied positions (because of their scarcity) and looks more like taken from a movie/theater than from real life. The general availability of color digital pictures, sometimes including audio and movies, should change this perception. I will not discuss here the issues that are brought by the smartphones ;) And, of course, you must have a way to securely backup your pictures.