Caller ID - Part I

Often I receive phone calls and get identify the caller with that handy 21st Century invention, caller ID. Of course I will usually answer with, "Hi Jane."

Often, Jane says, "Hi Justin, how did you know it was me?"

At this point, isn't there really only one way to know who is calling? Do people assume I have some psychic ability and can identify a caller without a caller ID function on the phone?