I wouldn't suggest casting off any of these dates.
I guess it really boils down what we attach or emotionalize to the memory. If the memory surrounds choosing unhappy or negative emotions, then I say the memory is not a useful tool, or it needs to be "re tooled" or reframed. (Some jobsite tools serve our project just as some life tools serve our well being.) Funny I just got a quote in an email today that speaks directly about this:
"Forget the past
and you will be doomed
to repeat it."
Rewrite:
"Stay present
and be happy
and you'll have
no reason
to remember
or repeat
the past."