In the early 1970s, when computers filled buildings and cost millions, I told a schoolmate that within our lifetimes, computers would be small enough to fit in a suitcase, be powerful enough to compose electronic music on, and only cost about £25k. He laughed at me!
As we now know, it actually happened 3 times quicker, they are a mere fraction of suitcase-size, and can be bought for far less than 10% of the price.
In the early 80s, I told my girlfriend that within 20 years, we would have affordable handheld devices that could be used to talk to people pretty much anywhere on earth, watch films on, take photographs, perform complex calculations with, listen to music on, etc. She thought I was mad!
I have a smartphone which can do all of those things. It weighs 100 g, is the size of a small bar of chocolate, and cost me only £75 on
eBay!
I admit that I did not anticipate the internet/web or GPS.
My forecast for the next 25 years ...? You aint seen nothing yet!