Pygmalion wasn't exactly what you'd call a social butterfly. When he sees a group of townswomen prostituting themselves, he doesn't attempt to talk them out of it or bring it up at the next town meeting. Instead, Pygmalion swears off all women, and locks himself in his studio. Well, okay then.
Thus, we get our image of the reclusive artist. This is the guy who can't really deal with the world and the people in it, usually because he's super sensitive. For this dude, art seems more real and truthful than reality ever will.
Often, after renouncing real life, the reclusive artist gets so involved with his art that he totally forgets about everything else. Sometimes he even has trouble distinguishing reality from fiction. Sound familiar? Yeah, Pygmalion is the ultimate example. Basically it's a three-step program to reclusiveness: (1) stops speaking to real women; (2) become obsessed with making a statue of a woman; (3) falls in love with that statue, and keep fantasizing about it being real.
If he weren't such a shut-in, the "reclusive artist" would probably be BFFs with the "mad scientist", since these archetypes share so many qualities. They both see themselves as the ultimate creators, and they usually become obsessed with the things they make. Dr. Frankenstein, anyone?
Of course, it's not only sculptors who have trouble distinguishing reality from fiction. The movies Synecdoche, New York, and Stranger Than Fiction show how different works of art can all become "real" to the people involved with them. Live inside your world of art long enough, and reality can get pretty blurry.
Oh, and reclusive artists are by no means confined to works of fiction. Examples of real-life reclusive artists include authors J.D. Salinger (Catcher in The Rye), Harper Lee (To Kill a Mockingbird), and poet Emily Dickinson. These people changed the landscape of literature, but just couldn't handle making idle chit-chat at parties.