Is there anything that you continually think about that upsets you?

How often do you make yourself upset with your own thoughts? And how often are the thoughts the same occurring ones that upset you?

For example, a really close friend of mine is a short man. His height is often made into a joke.. he actually finds it offensive. Although he laughs it off, he wishes he was taller.. and even when he thinks he accepts it sometimes, the thought will linger back into his brain.. the thought where he wishes he were taller, and that thought upsets him.

So, do you have thoughts that you keep thinking about that upset you? What is it? How do you keep from making yourself upset with your own thoughts?