Dear Georgina;
About once perhaps being able to choose your history:
Indeed it is not necessary to clean up the memory you have on the life-line you are now aware of, each life line has his own history and future , you just "jump" to another one with a "better" past, the one you were on is becoming one of the infinite availabilities. You can say that when this happens you will not be aware of this "improvement", that is true for the state of mind we have just now, there are I think however pasts and futures where mankind will have the possibility to make a choice , making a choice means also that you can compare life-lines, so the histories compared are becoming a part of your "real" awareness.
These life-lines can be compared (because we have to make a causal comparison)with the lines on a cone , the NOW is the centre , a point with no dimensions, a non-causal singularity, a scale invariant entity that represents the "Eternal Now". This singularity can represent the absolute nothing or the infinite ALL, because it is not imprisoned in dimensions. ALL possible and impossible life lines are passing through, so at every Eternal Now moment consciousness (if it ware able to) has the possibility to choose which way to go or which way it went.
In the life line that we are experiencing now, so only on the Eternal Now moment there is the possibility to change, in the history of your "present" life-line there are no such moments. However the Eternal Now moments are the RYTHM of reality, the Planck time.
This is in concordance with my perception that behind the Planck length and time there is another dimensionless non causal indescribable universe which is the singularity that is both ALL and Nothing, Total Simultaneity.
This thought is becoming now more accepted as the top-minds in theoretical physics and philosophy, among them Leonard Susskind posed the idea that in the center of a black hole there is not a material singularity but at the Planck length a wormhole that gives admittance to other universes. What I propose is that once you are passing the Planck length you enter Total Simultaneity, but not only in the centre of a black hole but at every point in our universe, so TS can be "reached" everywhere, the wormhole not only gives entrance to another space but also to pasts and futures.
see for this NEW SCIENTIST of 27th july 2013 page 10 : The great Quantum Space-Time tangle.
Our non-causal part of consciousness "resides" in TS, the Eternal Now, the dimensionless entity and is through entanglement connected with the causal part that is captured in dimensions.
I hope this explains a little, I know it is difficult to grab, it is just one perception and I am still working on the complete OEUVRE.
best regards, and do not hesitate to ask me if you have more questions, it is also me when I answer them that is learning.
Wilhelmus