They continue to haunt like growing mould on a left over pizza.

What should we do? Throw them out in way that lets us feel empty? Or
just move on? Neither seems to really work.

The only single way I know to move on is to grab the tail of a passing
emotional comet and let it drag me through the detrius of what once was
into something that has never been. Did you know that comet tails
preceed the comet? There's your analogy. Anything left behind cannot be
ignored beyond being food to feed the now.

Learn and then grow old learning. Proceed yourself with awareness that
what is can only be a prerunner of what was and always has been.
Whatever it is that makes you what you are is something essential to
who you will be.

There is no past with out a future. If you say that this makes you sad
then you haven't grasped what will be. Tomorrow is only a reflection of
today. So make today worthy of tomorrow.