To put it frankly, most people don't get or refuse to get it, no matter how well you explain it. A lot of people look at it as an excuse for bad behavior. I would tell people bits and pieces on a need to know basis only. "Sometimes I get angry really fast" or "my emotions can change very quickly" is about all I'd personally say. If the relationship gets close, then maybe more, but I honestly don't know how you can say it or put it that it will be be taken in a way not intended. Not meaning to be negative, but I've had very bad experiences with this.