when is it over?

How do you know when it's over? When it's gone? These past few months I have seen a lot of ghosts, and I've been trying to figure out the answer for myself. Once it starts, is it ever gone? Forever? Or is it always a thing, or a thing that used to be a thing? I know you can move on, and get over it, but can you simply get rid of it? Or is everything a forever thing? xx