Manker: If you know what 'you've got mail' means, recognize Donny and Marie or remember the Mir space station, you are old

From time to time something hits you in the face to remind you of the many differences among the generations.

Have you made a call using a rotary phone? Sent printed information via fax machine? Played your favorite songs on a cassette tape or an 8-track? Many of us have. And some of us barely...