Recall and reflect (in your mind or in your conversations) a family story that you heard as a child. The story may be a fragment- in fact, that is how most stories are handed down.
Now, write a list of the details you do remember. You are not writing a narrative, just making a list. Don't try to write text, just use short sentences, words, or phrases.
You may want to include: Names, relationships to others involved in the story, the place and event, perhaps describe the house or circumstances around the place where the story took place.
Be as specific as you can with details. What were people wearing, what might have been playing on the radio, who else was present, what was going on in the outside world?
Using this list (which will help you to reflect on the point you want to make with this story) Writ a rough draft of a manuscript.
Keep this rough draft in a loose-leaf binder as a working copy.
This may or may not end up in your story.
Now, use this list-making method to write down some other anecdotes or stories.
You are simply making small in-roads into your memory.