When was the last time you reviewed a conclusion you reached a year ago? Two years ago? Is it possible you made a mistake? Were you using limited references? Is it possible that new records or indexes have come online that might give you more information and cause you to re-evaluate your conclusions from years ago?
A correspondent a few months ago asked me about a person I had researched five years ago. She questioned the person I thought was the father of the common ancestor. In looking over her research, I ended up agreeing with her conclusion, but for different reasons than she gave.
Review what you've done before--the perspective of time may give you cause to change your conclusions. Or not. But it never hurts.