When writing memoir we start out intending to write about a time, a place, an incident, a person. As we write, our memories start to flow. We cast a spell over ourselves. This can lead to writing things like, "I can't remember what happened next but...", or "I think he said," or "It may have been..." These words are the product of the mind as it tries to remember. When we are under the spell it's important to us to try to piece it all together.
Knowing that the writing process triggers the remembering process, I would advise writers to just keep writing as they remember (or can't remember.) Don't stop to edit. Editing can break the spell. Indulge in the memories. Let yourself feel the fun, the sorrow, the pain, the confusion of the time you are writing about. When you have a first draft, then you should go back and edit.
But even this draft is not the time to "break the spell." Edit a first draft of a memoir with the intent to include more of the memory. Work harder to remember. Look at old pictures. Read old letters. Can you remember things people said?
When you feel like you have plumbed the depths of your memory and written everything you wanted to, then you should break the spell.
WHY "BREAK THE SPELL?"
You break the spell so that others can experience the memoir for themselves. How? By editing out all the words that were written that don't add to the power of memoir. Among those words will be the ones listed up top. ("I remember.", "I don't remember," etc.)
After editing out these words you should edit out the "equivocation" words like, "it seemed," "I think it was," etc.
After all those words are gone you can then treat the piece more objectively. Your critical mind can take over so you can read your work more objectively. Where will the reader get confused? Where might they want more about certain people or incidents? Is the punctuation correct?
In a sense we are two people when we write memoir. First we are wholly ourselves. Then we become writers hoping to engage an audience. Often that audience is just our family and friends. But they too will appreciate a story well-told.