As for the Topic of the Day...
Since I was on the road at the time, I would love to go back a few years for the birth of my nephew, John Michael, and my niece, Alyssa. I did not "meet" John until he was a year and a half old, and Alyssa when she six months.
As for the more catastrophic world events... As other DRs have hinted, Good does come out Bad, and, yes, even though it would be wonderful to change history, one does have to wonder just how much history one would be changing in the process.