The point I was trying to make is their are merits to playing a character completely different from who you are separately.
I think the point Christopher was making is that an effective character needs to have a basis in who you are. I agree. Otherwise it comes across as being inauthentic. If you aren't funny in real life, your character won't be funny. If you can't make people feel that you are caring and genuine, you can't express that in a character. If you aren't usually a serious person, it will be difficult to carry off a serious persona. If you aren't intellectual, you will find it hard to portrait a character that is.