I failed speech because I couldn't bear to speak in public. Until I took a class in college that was the key to graduating I didn't ever like it. But once I realized I had to do it, I started to like it. And now, I do it often, and love it.
It bothered me a lot up until my current job. I had to come up with an improvement project for my manufacturing area and justify a cost saving in a presentation to management and my whole group of coworkers. Everyone had to do it, but mine was the only one that got implemented. I was very uncomfortable during the presentation, but at some point, my Leo arrogance kicked in.
My advice now is to leave introverts alone. They don't want to me messed with. They have quiet time alone to think up a lot of complex and bizarre concepts. They can rattle them off extremely fast and make your jaw drop. The last thing an extrovert wants to deal with is an introvert that takes over the whole room and doesn't give a damn what they think.