Trudy Truly

I was reading the "internet" today - by the way, have you read the "internet"? You simply must! I'm almost done with it. Don't tell me how it ends! - and discovered that the person who portrays Trudy on MAD MEN is also the star of a current sitcom of which I have seen several episodes. But I never knew she was the same person! What can the explanation be? 1) She is so good at her job that she completely transforms herself into whatever character she plays. 2) I am a blind old man who is dumb and not terribly observant. 3) I am delusional, and whenever I watch MAD MEN I think I am spying via a magical device on real people living in a different time or plane of existence, therefore my brain cannot accept that an actor might be portraying one of them. I believe it's a combination of 1 and 3. With some 2 mixed in.