La moustache

Marc is sitting in his bath one morning and asks his wife, "how would you feel if I shaved off my mustache?" She doesn't think it's a great idea, for the 15 years they've been married, she's never known him without his 'stache. He shaves it off anyway, but when he sees his wife, she doesn't notice, neither do their friends at dinner that night, neither do his co-workers. Marc finally flips out, shouts at everyone, tells them he's tired of their little joke, and what do they really think. His wife and co-workers are appalled, what is he talking about, he's never had a mustache. In fact, he's imagining other things as well, or is he?