Why do people only appreciate when they lose it?

Why do people only appreciate when they lose it?
Today, you wrote me a really long essay..
You told me u forgive her even though she didn't treat you well
but sorry..I cant forgive
I am not you and therefore, she is not me
You told me its not easy to hang out with her anymore. Well, this is how I felt now towards you..How do you feel?Do you ever care about my feelings?
U regretted..Does that make a difference?
Your words...No..I shall say ur action, could not be taken back.
You begged me not to stay beside you but u begged me to keep in touch with me. U're telling me we dont know the futuer? and maybe one day we can still be together?
No way..
I cannot do it..I no longer want to see you appear in my life. This is enough and from now on, I want to protect myself.
7:00
another msg from u
u're saying that u're afraid that u cant keep me?
Between us..there are lots of obstables...
u dare to face me..we've been through alot
Respect me please...I really dont wanna get further into in..