Part of thinking about our 50 year marriage was making a timeline with the aim of at least one event for each year. With a little effort, we could be clear for any year, our own ages, the ages of our children, where we lived at the time. We could remember what job we had, what our income was, what church we attended. We have found that the properties of digital photos stored on a computer often give us a clue as to when a picture was taken and we find that most of the time, we can recognize the people or the place it was taken. Still, we did have a few years that seemed to leave no memories or markers, although we doubt that a year went by without several notable shockers or pleasers coming our way.
One of the nice things about the Kindle is that Amazon can tell us the date and contents of every order we ever placed with them. Knowing when we bought a book or a gift often gets us thinking about our situation around the item in time and space. We find memories buried in associations with giving a certain gift or reading a given book.
Of course, just as with Maurice Chevalier and Hermione Gingold in "Oh, Yes, I Remember It Well", the two of us sometimes remember events differently. As with many husbands, I have found that if there is simply no way to judge who is right, the odds are she is. There have been occasions when one or the other gets dogged and eventually finds a way to unambiguously establish what the facts are. Although we have a running agreement that in cases of dispute, 2/3 of the time she is correct, the actual fact is that she is right more than 90% of the time. All the more reason to tap her memories and write them down while you can. Of course, your kids and grandkids are too busy now for reading or watching your records, eventually they or their own great grandkids will be appreciative of the fun you had collecting, collating and writing.