If it won't matter after 72 hours, it never did.
If you won't feel the need to react after 72 hours, dont at all.
If they know you're hurting and haven't checked up on you in 72 hours, move on.

It's kinda sad when you realize that the person you used to tell everything has now no idea of what's happening in your life. Ego is a hell of a drug to be honest because the person you love is probably pretending to not miss you and you're pretending like you don't care.
I just wasted my time. I counted the amount of hours which would take the person to remember me but after 72 hours I stopped. It was time to say goodbye.