When you lose a close one you often feel that stab of pain that just won't leave and that will stay with you. That is ok, it's not something to forget about, for the more pain you feel once they're gone, the more you were happy when they were with you.
As such, pain is what allows us to feel joy, and we should never resent it. We can take it, and move onward, knowing we have been happy about something at various points in our past, and we likely and hopefully will encounter more happy moments in the future.
It will not leave, not completely, and it is a reminder that we are not devoid of feelings. We can learn to live with it, in time.
Even after years, a memory will trigger and a tear will fall. It happens, we'll smile and keep going, because there's only forward.
It is a strict and disciplined teacher that allows us to appreciate things.
So farewell, and thanks for the pain, I will cherish it just like I will all the good memories.
(Just a plain and straightforward thought out loud I have attempted to convey in text form, moving on)