A "futurian" (p. 169) time traveller asks a temporally displaced twentieth century man:
"'If it were possible, would you want to lose your past? Out of it must come your tomorrows.'" (p. 168)
We are not told whether it is possible to "change the past" in this scenario. Time expeditions are few and none are wasted on revisiting the near past so maybe this question does not arise, as it does not in the novel.
How might we "lose" our past? Amnesia would be one way. In the Time Patrol universe, someone who prevents his own birth and earlier life will nevertheless continue to remember that earlier life and to be the kind of person who had resulted from those "deleted" experiences.
I can see that, if my past had been different in various ways, then my present and my tomorrows would have been unequivocally better. Specifically, I would prefer to have been brought up by people who had some understanding and respect for alternative points of view. So, yes, if it were possible to live again, then I would prefer to start in a different place.
A dialogue from earlier in life:
Another young person to an adult: Why should I believe what you want? Why shouldn't I believe what I want?
Me to the other young person: Why believe what anyone wants? Why not find out what the truth is?
The adult to me: Don't YOU know what the TRUTH is?
Me (to myself): No, I don't.
Me to the adult: I'm talking to her!
It took me a very long time to think all the way outside the box, partly with the help of science fiction.