How difficult would it be to describe flying in an airplane to someone from 1850? Pretty difficult. For someone from that era there is no relative comparison - nothing even comes close to that which can be used as an analogous description of today's air travel.
How difficult would it be to describe the Internet to someone from 1900? Somewhat difficult. In the era where labor (both physical and machine-based) was king, a worldwide information network would mean very little to the common man. Yet the value of information, particularly that of the newspaper, was quickly expanding.
How difficult is it to accurately imagine what radical innovation the near-future will bring? Not easy, but not impossible. We are more connected to the future than any generation before us. It is exactly the radical innovations of air travel and the Internet that make tomorrow more tangible. It's now nearly impossible for the future to hide and grow in a little, hidden cave.