I see that actors Martin Sheen and Emilo Estevez (father and son) are writing a joint memoir called "Along the Way."
If you have been thinking about writing your memoirs, whether for publication or as something to pass along to your children and grandchildren, this could be an interesting model. Or you and your spouse or significant other could collaborate, writing about the years you have been together and also the years before. (Probably best if your relationship is very secure because one of the things you will discover is that you have totally different versions of various events.)
(My book, 'Your Writing Coach," includes a section on writing your memoirs or autobiography. You can get it at Amazon and other online and offline booksellers.)