They want to do as little work as possible because if not, they are doing something selfless, which is not who they are.
Because they aren’t built for compromise, and solutions when the only thing they see when looking out into the world… Once a selfish person has seen all you have to offer, or the relationship is coming to a point where they need to start giving, they will call it quits because it no longer serves their interests alone.
When that happens, it’s time for them to leave and become someone else’s parasite.
They let you know what they’re doing at the last second because if something better pops up that’s in their interest, they’ll take that route instead.
This is because they don’t care about you, they care about them.
I’m not going to try to play shrink to figure out how low your self-esteem has to get for you want to win back a psychotic, selfish, abusive commitmentphobe, but let’s say that what happened to you should have driven you far, far away from this guy.