Over the weekend my wife received some old photos from her mom. It was fun sharing these memories with the kids and my wife stated that her mom even gave her the negatives. My 12YO daughter looked at us blankly and asked, "what's a negative?" The wife and I look at each other speechless for a moment.
As with 8 track tapes (before my time), cassette tapes, LPs, 5 1/4" floppies, and so forth, everything evolves. It will be interesting to see what items we regard as staples today will be gone/modified in the (near) future.