[kqr]

I think this has less to do with age and more what we are taught. The printing press, steam engine, and the wheel were repeatedly drilled into me as world-changing technologies, so those are the ones I'd think of.

But there are more. Rope is arguably more important than the wheel. Their combination in pulleys to exchange force for distance still astound me, and is massively useful.

Writing lets us transmit ideas indirectly. While singing and storytelling lets ideas travel generations, they don't become part of the hypothetical global consciousness as immediately as with writing, which can be read and copied by anyone once written.

I'd put statistics in this bucket too, its invention being more recent than 600 years. Before that, we just didn't know how useful information is in aggregate. Faced with a table of data, we only ever looked up individual (hopefully representative) records in it.

[driscoll42]

To suggest another "simple" example, Air Conditioning. It made half the world vastly more livable, and now anywhere in the world you could work every day of the year, reduced deaths and disease. At least currently, AC has had a greater impact on humanity than AI has.