Changing the Past?

Three quotations on changing the past:

[He] thought, even if it was not true that he was a hero, perhaps it was true that he was not a criminal or a failure.  The possibility existed for him that the past was mutable — that he might have a new truth, a new narrative that was truer than his own tortured memory.  For the first time, he realized how subjective it all was and how the past was not as inviolable as he had come to believe.

Matthew Hefti, A Hard and Heavy Thing 207 (2016).

Now for you and me it may not be that hard to reach our dreams,
But that magic feeling never seems to last.
And while the future’s there for anyone to change, still you know it seems
It would be easier sometimes to change the past.

Jackson Browne, ”Fountain of Sorrow,” Late for the Sky (1974).

Time present and time past
Are both perhaps present in time future,
And time future contained in time past.
If all time is eternally present
   All time is unredeemable.

What might have been is an abstraction
Remaining a perpetual possibility
Only in a world of speculation.
What might have been and what has been
Point to one end, which is always present.

T.S. Eliot, “Burnt Norton” l. 1-10, Four Quartets (1943).