Eighteen is the age when unrestricted OC becomes legal. Whoever you were talking to had no idea what they were saying.
I would suggest a read of the Kentucky Law thread at the top of the Kentucky sub-forum.
ETA: I tried using the correct form in citing the title of the thread (italicized), but for some reason that function wants to italicize the entire portion of the sentence after the title. Am I doing something wrong when using this feature?