something hurt ?

sometimes i feel like i really miss everything in the past,
but when i remember about something hurt in there, that's really sucks .
something hurt that including someone that was make it for me .
i always think that i should be able to forget about something hurt .
but i can't when i try to forget, i feel like i really hate about it, everything about it .
and i don't know why can't i forget it, why can't i like everything about him .
he always be in the wrong time, when i feel i'm happy, suddenly i saw him,
or there's something that make me remember about him and my past .
you know, i don't know what to do,
no one can understand what i feel except my self,
people in easy say "udahlah lupain aja, kan cuma masa lalu" or "sabar ya",
or "don't be like that it will hurt your self " or just smile,
oke thanks about it\, but i cant do that .
i never feel comfort with this,
one of my friend say,  " someone who hurt you is someone who makes you stronger, and never hate them because one day they'll feel the same ;) "
that's right,
but i don't know what this feeling meant,
"somettimes when someone hurt you, you will hate what he does for you, but you can't hate him ever"
and i don't know, the words above is right or wrong,
but i really want forget everything about him, everything :(