I met a student who told me "I am an agnostic." Whenever someone confesses a worldview I ask, if I have the chance and it seems appropriate, "What do you mean by 'agnostic'." I know what the term means. But I find many who use these worldviewish terms (like, e.g., 'Christian') don't know their meaning.
This student replied: "I'm not sure." Which I interpret as: "I don't know."
When they said that I thought, "I have now met the perfect agnostic; viz., someone who is agnostic about the meaning of agnosticism.