Over my lifetime many things have changed:
- Eisenhower changed from a middling president to something more, worthy of a monument on the Mall.
- Grant changed from a president presiding over corruption to a protector of black civil rights.
- Sadat changed from a tinpot dictator and Nazi lover to someone who risked and lost his life for peace.
- Bob Dole changed from a partisan hatchet man in the 70s to a well regarded last remnant of the Greatest Generation and a very funny man.
- Ian Paisley went from pope hater to almost a statesman working with the IRA.
- some people change over their lifetime, both as they change and their environment changes
- how people are evaluated depends very much on who the evaluators are and what their environment is.