I can see your point of letting things be as they are, szts77. I guess I would go back only to find some answers and be amazed at how they did things.
Like Glydenboy, I would like to see if there was an Atlantis and yes, how the ancient pyramids were built would be incredible viewing. I, too, would want to be invisible, not like Kirk and Spock, lol. :)
I would love to see who was my dad's mother, father and family since he was adopted and I have all this love for music, the arts and many other things. I feel that some of it came from downline. I also would like the plague that killed all of my dad's family and what diseases prevail in his lineage. His ancestors came from England and that would be one of my stops, also.
To know my heritage would be so cool, because I love the Native American culture along with ethnic ones and always wonder if I have some of that blood in me.
I guess if could change anything, it would be Hitler's destruction of all the Jews, America's bloodshed of the Native Americans, the slaughter of so many by ruthless terrorists and the horrid crimes against children, but then as C.S. Lewis said "where do you end suffering?"
The free will of man is what causes it and God gave us that until the time when His judgments come upon all mankind. I sure cannot take God's place or I would change the free will of humans in this time frame we live in on this planet.