My psychologist feels that it's not good to think in black and white terms. She says that people who think this way tend to have low self-esteem and may be more likely to suffer from depression.
I think she may be right. When someone thinks in black and white terms, they may be very positive or very negative about issues. Being positive is good, but when situations are seen in a very negative light, it can be depressing.
I tend to think in black and white terms sometimes and I need to change that. If I realize that things are not as bad as they seem or as great as they seem, I won't be disappointed so often.