Often times it feels like I'm back in highschool, but looking through from the other side of the glass. I see what my mistakes were, but the only problem is that I'm dealing with adults twice my age in most cases.

When your students fall asleep during lecture, despite all of your attempts to keep the conversation interesting and active, then you know that it is time to draw the line. How would you approach that student to let them know that what they have done is wrong, without letting your frustration get the best of you?