Self-respect sounds like “no” without a three-paragraph explanation attached.

Over-explaining is a way of asking for approval on a decision you have already made. A long justification invites debate, because every reason you offer is one more thing the other person can argue with. The length is usually proportional to how guilty you feel rather than to how complicated the situation is. A short answer closes the topic without any hostility in it.

Say no to one thing this week in under ten words. I cannot make it, thanks for asking. Then leave the silence that follows alone, because the silence is where the whole habit lives.