Do fake people know they are fake?

I am really wondering whether people who "act" like something, or someone know that others can see that they are doing so. I mean if somebody just meets someone, then obviously that person wouldn't know what that person really is like.... But if the person who is acting phony nice or phony religous does so in front of people who know that they are really like....I think I am pretty real....I never put on a show to try to impress anyone, and don't act like I love Jesus just because I am in the presence of a Priest...or whatever. However I do know people who do so.....and they continue to do so, even if someone who has known them for along time is right there......I really have no point to make in this but just had to say something about it.....fake ass people!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!