Nerves are always a big problem for me, which is why I loved doing American sitcoms. Because you know when you do the take in front of the audience that you're going to do it again afterwards. A minute after you finish, you just go and do it again. So, there's that sort of safety net. And then if you made a little mistake or two, they'll go pick it up, so there's nothing to worry about.
John Cleese