Philosophical question - NOT amateur radio

Every now and again, I ask myself a philosophical question.

This time it is about the nature of time. We usually think of time being a linear thing going from the past into the future. We assume our memories are records of past events. However, it is entirely possible that time is an illusion. Perhaps we think we have memories, but these are illusory. Indeed, our awareness of space may be an illusion.

One thing we know is how limited our brains are. Every year we seem to learn new things about our universe(s). In 50 years' time we may look back and say, "did they really believe that?".

Imagine you were suddenly back in 1819. Would you have believed in aircraft, moon landings, the internet, radio, TV and quantum physics? Even in 20 years things have changed a great deal. My wife is reading a book written in 1995, when pagers were the "in thing" and nobody could imagine how mobile phones and the internet would develop.

What will we take for granted in 2119 that we know nothing about today?