Public speaking
When I went back to school one of the courses I had to take was speech. My instructor found it amusing that I taught for a living but was unable to participate in the class without freaking out each time I had to speak. I even used one of my lessons as a speech and still struggled. For me it is not the lack of knowledge that did me in but the feeling that I am being judge. When I reach my students are so eager to learn that I am not aware that I am talking in front of 30 people. I feel that I am just talking to friends that want to hear about ECG's.
I am not a teacher, but I feel the same way. When I speak in front of children I am so much more comfortable than in front of my peers. Maybe imagine in your head that the audience is children :)
I have found that when I am focusing on myself (feeling like I'm being judged) is when I get nervous. However, as soon as I am more focused on the audience (are they getting my message) the nervousness falls away.
I was once told that Butterflies are normal, all you have to do is teach them to Fly in formation (via practicing your speech).
