You remember them, the objects with two spools which some of our children may never have seen, along with those objects which one Mumsnetter's DC described as "like CDs, but big and black".
Although I don't use cassettes very often, with my dislike of built-in obsolescence which seems to be designed into many things these days, I have kept many of my old video cassettes, and the technology to play them; sometimes I use it if I fancy watching an old show. There's something quite satisfying about loading an actual cassette, and hearing the video player whirr into action; and having to wind the tape back.