Do you travel light by leaving the past in the past as you move forward in time? Some drag baggage that gets heavier and heavier. WHY?

It slows them down and what's worse makes them sourpusses. Cranky whiny complaining about this and that and the other that happened decades or years or weeks ago. SO WHAT? Why do it?

I know. If we don't LEARN from the past we keep reliving it. Why can't we LEARN and move on? What's the downside to that?