People with BPD can be very sensitive to the way others treat them. They can feel very happy and grateful when they feel someone has been nice to them, and very sad or angry when they feel someone has been hurtful to them. Their feelings about others often switch from positive to negative if they feel like they might lose someone, if they think someone important to them does not care about them, or if something is not as good as they expected. They think in extremes, seeing things or people as "all good" or "all bad". This is sometimes called black-and-white thinking. It includes a change from admiring someone to devaluing them, often feeling pure anger or dislike.The way they see themselves can also change quickly from positive to negative.