I've never been a very good public speaker. Even though my mom always says, "What's the worse that can happen?" my heart still begins to flutter and I stumble over my words when it comes time for my time to speak. I was in Forensics in high school- maybe that's where it started. Having your first public speaking event in front of other mean 9th graders isn't really the best experience.
I would have to say, though, that my worst public speaking experience was even later in high school. I had braces for 2 years and for about 9 months of that time, I also had an upper mouth piece that caused me to speak with a lisp because it was widening my jaw. Well, i won some award and had to give a speech at the meeting saying thanks. I thought I did ok until someone in the audience approached my mom and told her how brave she thought I was- she thought I was learning disabled because of the way I talked! She also spoke to me like I was a 5 year old. Talk about totally mortifying!