I've been teaching for about 10 years now and one habit I can't break is cutting off the students before they complete an answer. I don't always do it but sometimes..... It is not malicious, but often the students answer will set off a new idea for me and I'm asking a followup or discussing the idea before the student finishes. I have tried to break the habit but without success. I often find myself at break time talking to the student and making amends. One of these days I'll figure out how to stop without forcing those long pauses… >>>