just had a small insight and did some quick mental arithmetic. hold on to your seat:

i counted, it's about 20 hype trends that i listed above (and don't forget that I may have missed some).

it is roughly 6 decades since the computer industry started, taking a start year of 1960.

so, 20 / 6 gives us an average rate of over 3 hype trends per decade !!!

about one every 3.3 years.

I myself would have thought it would be less often.

even if you make it 7 decades, 20 / 7 is nearly 3, so is still in the same ball park.

phew.