Right? I can brief things to an audience of people at work without any problem (once I get started, that is; I'm a nervous wreck up until that point, though). But talking to a camera is just freaking weird.
I made a little intro video for my channel the other day. I started/stopped the recording nearly 30 times before I finally got off on the right foot. I don't have time to learn editing software at this very moment and the need wasn't high, so I was just shooting from the hip. Ironically, I mentioned that I wanted my video to be family-friendly because I always have to delay watching some of my favorite shows/videos until my kid goes to bed due to the language. But I'll be darned if I didn't belt a few choice words out after each of my 30 initial tries.