>Something we have never thought?

probably this. or at least, something we HAVE thought of, existing in a way that we didn't forsee. like look how the original star-trek didn't really even think of NOT having buttons, switches and tape or whatever cartrige storage for computers?

I think that trying to avoid this we are prone to projecting future tech as functionally magic, but maybe the unforseen part is it being totally mundane to do something that we assumed would be magical.

then again, I'm sure commercial flight would be seen as magical to the wright brothers, and to us its pretty mundane.