Learn to forget??

there was a message sent to me saying that..
"if u love something, set it free.
If it come back to you, it is yours.
If it doesn't. It never was.."
many people ask me to forget about the past..
i know that everyone did this because they hope that
i will live better than the days before..
and out from the pain..
but actually..sometimes..
if we cant forget why should we??
sometimes we can try to put it in our heart..
if we cant forget then just let it be..dont try to force ourself..=)
all those good and memorable memories..
i wont forget..=)
just take it as a lesson, and we will be a beta one in the future..=)
i believe this^^