Public Speaking Struggles: Is It Common?

I gotta say, I'm kinda shocked that some people seriously struggle with public speaking. Just the other day, we had a get-together with friends, and someone was supposed to host, but they just froze up. It made me realize that not everyone can express themselves well in front of others. Like, is it just me or are there more folks out there who prefer to keep things private? Seems like some would rather talk one-on-one than face a crowd... Anyone else notice this?