I remember being astounded by my first 50MB harddrive. Then again by my 500MB drive, and my 2GB, 200GB, 1TB drives over the past 20+ years. In 1995 I could get on the internet and surf websites using Windows 95 and netscape. Not all that different from how I surf the web today.
There is an astoundingly huge difference between surfing the web today and surfing the web 17 years ago!
When discussing computer technology, things seem to operate in shifts and rises. In other words, technology is linear until a major shift in technology, such as the integrated circuit. I expect we will continue to see linear growth in computing power until the next major shift, be it holographic technology, dna based computing, or something nobody has thought of.
However, denying that changes in technology is accelerating is difficult to do. Humans alive today enjoy technology that couldn't be imagined in 1900. Humans in 1900, however, weren't living all that differently from a technology perceptive than humans in 1800.
Whether the next 100 years will offer the same range of advancements as the last 100 is pure speculation, however.
Its not deniable, facts are facts. People wouldn't recognize how we live now in 1970. Culture, events, technology are so different. The difference is magnified with 1950s era technology. It used to be people could ignore technology, now it's extremely hard to do and requires effort. Even so, what humans perceive in our limited way doesn't even scrape the surface of real change happening underneath. Its as I said, its not about something as pedestrian as flying cars, its about the info technology!
Edit: This brought back memories of me on the internet early 90s, and my own first PC...upgraded from IE2 to 3, the simple pages loaded slowly, Real Audio was a pain in the ass....to think I STREAM VIDEO to all my video playing screens all over the house now seems unimaginable!