When people talk about parting, the general metaphor is “cutting off ties”. As if you were bound together by ropes. Which also implies that the relationship wasn’t a good one because ropes are associated with bondage, keeping something beside you which doesn’t want to kept. So it’s only natural to let go.
But sometimes parting is more like the painful and tedious rubbing of sandpaper against rock, trying to erase something which you’d set in stone. It’s tiring and lonesome work.
Anyways, here’s a song about parting. Ending Scene by IU. 
A little bit of everything 