On page 56 of the May 11, 2019 issue of New Scientist magazine there was an interview with Tanya Harrison. She is a planetary geologist and director of the NewSpace Initiative for Arizona State University. When asked what the best advice anyone ever gave her, she replied:
“A friend once said: ‘Remember, you know more about the specific thing that you are talking about than anyone else in the room. Be confident in that.’ That really helped me get over my fear of public speaking.”
The cartoon image of a confident female speaker was adapted from one at Wikimedia Commons.