They will not change and you will only have yourself to blame for being subjected to their negativity towards you, over and over again. Believe who they are the first time they show you. Wish I would have realized this a long time ago.
Character is revealed in certain, sometimes subtle, ways. For example, pay attention to how people treat waiters/waitresses and anyone in jobs of service. When someone shows you who they are, believe them the first time.
Maya Angelou - Believe them the first time, when they show you who they are. you showed me who you were before, I just refused to believe it. I'm too nice. Took a long while because of my heart but I'm better off without you.