Og and Trog were creeping up on the megatherium, and each slowly nocked an arrow to prepare their attack. Only two men attacking a huge ground sloth was borderline doable, but they couldn't pass this up. As they drew back and began aiming, Og's bowstring went "twang!" and broke.
"Well crap" he said. "I didn't bring a spare, have you got one?"
Trog said, "Sure; here, string it up before this beast gets away."
Og took it and unrolled it, and began to string it, but then he looked at it for a bit, puzzled. He then took one of his arrows, and tried to see if the string would fit in the arrow nock, which it did not, it was too thick.
He looked at Trog, and hissed "What the hell is this?"
Og had been staring intently at the megatherium, but turned and looked at Og, who was almost hopping foot to foot, so anxious was he that the tribe's next week of meals was slowly shambling away, and he had no functional weapon.
Og whispered back " Do you mean you are still using the OLD strings? Bog has been making the new stronger ones for four moons now. I can't believe this!"
Trog was purpling around the temples now, and said "Nobody told me about this crap, and you know I've missed the last three hunts with that leg the wooly rhino stepped on!" He sputtered "And besides, the old strings worked just fine."
"Well", Og said, "We don't dare try to take down this beast with only one weapon, I guess we are screwed."
Being paleo-Indians, they didn't talk much. This had been a remarkably extended conversation, brought on by extreme duress. They silently trudged back home, knowing that by the time they rearmed, the big lug would be long gone.
And so Og and Trog's tribe did not make it through the winter that year. Oh, there was still some game around, but it was getting more scarce every year, what with more and more mouths to feed, and another tribe taking up residence just two valleys over, and all the smaller game seemed to be quicker and more wary than the big lumbering ones they had relied on for many generations.
14,000 years later:
Steve remembered that he had tucked away the Home Power magazine collection on CD when they had moved, but had't looked at them for ages. When he had finally decided to move to a Mac instead of a PC, that had been one of the main reasons he made a point of purchasing the accessory external CD drive, since the Mac had no disc drive. He was thinking this might be the year to do solar thermal water heating, and wanted to go back and pull up the best articles for review.
He fed the first CD into the drive. It hissed and clicked, the software finally launched, and the table of contents came up on the screen.
The first article he clicked on did not come up however. Instead, a message said that Apple no longer supported power PC. "But these are PDFs, why does that matter?" he thought. Steve, not being a computer whizz, had no idea why the Mac was not backward compatible with what he thought was a universal format.
He played around with different ways of trying to get at the files, but to no avail. How odd, the table of contents come up, but not the individual files. This was over his head.
He then used bad language, a bad habit which showed no signs of going away.
Yes folks, all those terabytes of research, heartfelt blog droppings, cat videos, and political memes that our species cranks out continually will be as mist over a pond come the morning sun. Slowly fading and gone forever. Oh, some of it might still exist in some sense, but after twenty upgrades and four format revolutions, it will be as useless as a Clovis point would be to try to start your car with.