The first reason that comes to my mind is to preserve memories. For years we three children along with friends and other relatives urged my parents to preserve their memories. “Tape record your stories,” we urged. “Write them down,” we said.
One year a cousin, Gerry Parker, set up a tape recorder to preserve my dad reminiscing and reciting some of the long looong poems he knew. But in the end we had precious little of his amazing life from a spinal injury when he was a kid to missing his last year of high school to take his widowed mother’s cattle north from the worst of the dust bowl to better pastures. We know little of how he achieved his dream to become a minister lacking the requisite education, or how he managed to buy the mountain ranch of his dreams. Only he fully knew the details and now they are lost.
Only you know the details of the important events of your life from your point of view (and how often another’s point of view is wrong!) I believe most private memoirs are primarily to let future generations know you and how the world was in your lifetime.
Another reason is to be an example, to teach a lesson. I just read a memoir with a primary message of “See how successful I was and you can be too.” I’m definitely guilty of that message too blatantly in some of my essays.
Very popular in recent years are conquering illness or substance abuse or abusive relationships stories. They are popular because they offer advice, empathy, and possibly hope to others in similar situations.
A fourth reason to write a memoir is to proclaim to the world what a wonderful person you are. I’ve read memoirs where that was the major theme, and again I plead guilty in a few places in my memoir.
Other memoirs seem to be primarily for revenge, to expose those who have wronged you, eg. Mommy Dearest and others of that ilk. Again I plead guilty: I wrote one chapter called “Terrible Awful Horrible No-good Bosses.” Those incidents were long ago and far away. But I refrained from writing about a very recent hurtful incident of blatant selfishness and rudeness of close relatives.
I’ve presented five reasons to write a memoir here. Can you add others?