Sometimes people disappoint you. Sometimes they are unreliable, illogical, irresponsible and impossible but you put up with them anyway, or so the experts say.
As for me, well there is a very simple test I use.
Do I notice if you are around or not.
If I don't notice when you are here or not I tend to just let you go because life is too short to waste on people who don't add to our lives and only take.