What does it mean, when you start to forget?

Someone asked me one day, what kind of books Sam liked. As I began to answer, I suddenly could not remember the title of one of his favorites. A book I had read dozens of times, over and over, and I forgot it's name. Once home, I immediately went to his book basket in our living room and rifled through until I found it; "You Can Do It Sam." Are you kidding me? A book with his name in the title, and I couldn't remember it. Who does this? What kind of mother, does this? I beat myself up over it for a very long time. It had hardly been more than a year, I shouldn't be forgetting this sort of thing. I couldn't be, shouldn't be, "moving on."

What does it mean when you start to forget? Are we really moving on, or is it just the heart's way of protecting us, softening the transitions of grief? I have often said that I will never get over the loss of my son, but I will one day learn how to cope. I try to be a little kinder with myself when I feel my grief shifting. After all, I forgot the name of a book, I didn't forget his name.