I should also add that although I'm an introvert by nature, I have no problem at all with public speaking (on any topic but my private life), I can stand up in front of literally hundreds of people and deliver a lecture, talk, or presentation and not just get through it, but do it well. I lectured at university level for three years, I did lots of tutorials, as a grad student I did a lot of presentations at conferences, including giving a keynote address, and I have given many talks about science and astronomy to schools and astronomy clubs.
In more recent times my public speaking is mostly in the form of audio and video podcasts, including live broadcasts and hosting shows with literally thousands of listeners.
I CAN do public presentation well, but I find it really takes it out of me, I'll be very worn out after a 2 hour show or lecture. So my natural state of being is introvert, but I can flip a switch to extrovert mode when I have to, but my extrovert persona is a mask.
B.