People magazine described Elizabeth Berg’s latest book, “I’ll Be Seeing You,” as “a memoir of dementia’s ravages.” And therein lies the decision whether or not to read this book. I chose to read this book because I’m a huge Elizabeth Berg fan. I have read all of her books and like most of them. But I wasn’t straining at the bit to read this one because I wasn’t sure about Elizabeth as a memoirist and wasn’t sure I wanted to read about anyone’s decline into Alzheimer’s. Elizabeth is an amazing writer, able to get to the heart of her characters. I think that’s because she is so authentic, so genuine, and so lovely. Her writing in this book does not disappoint. However, a caution: If someone you care about is experiencing Alzheimer’s, or if you are worried that you are, this book might not be for you. On the other…