I think you need to know enough and accept enough to understand the impact it all has on you in the present day.
Do you need to remember everything that happened? Nobody remembers everything that happened.
Do you need to have a complete memory of any one incident from beginning to end? Nobody has a complete memory of childhood things anything that happened from beginning to end.
Traumatic memory isn't even stored as a narrative story. It's stored as fragmented sensory impressions. If you have random fragmented sensory impressions of childhood trauma, that IS traumatic memory. That is the very definition of it. But even then that doesn't mean that your sensory impressions are the one and only definitive truth about What Happened. All we can really take it to mean is that this is a thing that is causing me problems / flashbacks and this is the thing I need to heal in order to be.... healed.
I kind of think nowadays that it is what it is. I don't need to swear on a bible about it. But this is my internal experience, like it or not, and to move past it I need to find a way to heal those fragmented sensory flashbacks in whatever way works.
If I have a recurring flashback of childhood terror associated with ____ is it going to help me to stand back from it and say "Well, I don't think that really happened" ?
I sure know that hasn't worked for me before.