James Caan told me at the end of filming 'Elf' that he had been waiting through the whole film for me to be funny - and I never was.
I can watch a movie and go, 'Oh, my god, that person is acting.' If you just listen to what the other person is saying, your response will always be genuine.
It is extremely dangerous to talk about limits or borders. It is vital, instead, that we remain completely open, that we are always involved, and that we aim to contribute personally in social events.