Disclaimer: I have no monetary stake in Grey's Anatomy. This is only a tiny interpretive snippet, and neither characters nor trademark phrase are mine.
Warnings: Most of my knowledge of season 1 comes from Wikipedia and Television Without Pity; apologies for what I muck up. After reading this, the word "McDreamy" may temporarily lose all meaning for you.
Any Other Name
These are the things that McDreamy is not.
She isn't the first one who called him McDreamy. Meredith's been using it to refer to him for so long that she's adopted it as part of her own personal vocabulary, sometimes forgets it was her fellow intern who came up with it. It rolled off Cristina's tongue without thought, on a whim, as a joke. It used to be a joke.
The first time she refers to him as such with her friends, she laughs off the silly nickname, refusing to put too much stock into it. The second time, she writes it down on a piece of scrap paper, curling the letters with a secretive smile on her face. She crumples the paper and throws it away a second later, but the image lingers in her mind and the name lingers on her tongue. Later on, it turns into a coping mechanism, a protective barrier against reality. McDreamy is nothing but an adjective for windswept hair and a charming smile. It is another word for illusion, everything a woman could want and nothing tangible to keep.
McDreamy is not Dr. Shepherd, her boss. Dr. Shepherd is a man who will make or break her surgical career, who will watch her cut into people at their most vulnerable, all the while knowing what it means for Meredith to be the same. Dr. Shepherd is unpredictable, alternates between indulgent and frosty, keeps her on edge. Dr. Shepherd is dangerous.
McDreamy is not "a guy in a bar." Anyone can be a guy in a bar. Joe is a guy in a bar. Guys in a bar do not whisper lines like poetry in the throes of passion and turn a drunken, anonymous blitz into a romantic fantasy. Guys in a bar are empty and looking for the next cheap thrill. There are times when she is too, so she goes along with them when she wants an escape. They never return, nor does she expect them to.
McDreamy is not her boyfriend. Setting aside the fact that she tossed that term along with her graduation cap, a boyfriend takes you on dates. He calls to say goodnight and tells you you're pretty, even when you're not. He brings flowers. A boyfriend also gets jealous, gets into arguments, and forgets you were going out to dinner that night. A boyfriend makes mistakes.
McDreamy is not – and this is important - and never will be Derek. The former is an idealistic fantasy, the latter is only human. The intimacy of his first name lets her look closer than she wants, marring the guilty pleasure of her perfect fantasy. Derek has opinions and interests, history, a family, more detail than she can handle. She knows enough about him, his fingertips against her hair and which section of the paper he reads first, and other things she would like to forget.
Derek has a wife. Her name is not Meredith.