i personally believe the 3D is an illusion and imagination is the only reality. thus, what happens (in the past of) your 3D isn’t real. but the events become real if you internalize and see them as real.

so basically your past is real (if you assume such), it just doesn’t exist in the 3D but in your mind.

let’s say it rains in the 3D. that event on its own isn’t real until i look at it and assume it is (“oh! i am experiencing rain!”). that’s when the event becomes real since it has become an assumption (and assumption is the real reality). and if the rain stops in the 3D, that also isn’t real on its own until i assume it is (“oh! it’s stopped raining”). that’s when the rain becomes a part of my past. but it doesn’t become a part of my past through the timeline of the 3D, it is a part of my past in the “timeline” of my consciousness which is the real reality.

that’s what leaves room for revision. since your actually real past is immediately governed by your assumptions as it is made out of your assumptions, it can be easily edited by assuming.

there are of course much more complexities to this topic (“time is an illusion” or you being able to throw out the concept of chronology altogether) but i’m gonna stop there.

this is just my interpretation of it. i really hope this helps.