You wouldn't be alone. The word "neocon" has been expropriated by media dullards to mean something quite unlike its original meaning, which was a description of someone who had come to conservatism after some defining event which tended to move forward as people got older. For some such people as Sidney Hook and Whitaker Chambers were "neocons" in their day; for others it was anyone after William Buckley's "God And Man At Yale," for others still it was anyone coming to a conservative viewpoint after Barry Goldwater.
How it came to be applied to such as William Kristol is more a thing of amusement than curiosity. The term today has lost all descriptive value and is used exclusively as a pejorative. It might as well be "poopoo-head," it's just about that deep. All IMHO, naturally - anyone who prefers this sort of catchphrase is welcome to it.