It is for this reason that I always put quotation marks around "time travel", your statements about parallel universes are not correct and I cannot explain why for security reasons.

Also because there is a bias in looking at the past from the present, or the future from the present. It is likely that even if I go out on a limb and explain it to you you will not understand it and it will seem apocryphal to you.

Understanding the existence of that bias was key to technological advancement.