I say, memoir-writing, at its most basic, is obsession.  Involuntary obsession is a requirement for the endeavor. (I have my mother’s genes to thank for an obsessive brain that won’t stop writing the book even when I—the more sensible one of me—wants to.)  Writing a memoir is like having a lover waiting, hiding in a hut out in the nearby forest.  Even if you can’t stay, you want to steal in and touch his cheek, even if it can only be for a second.