pre-history civilizations barely communicated with one another. Entire cities or in this case, settlements were lost with no indication of who or what they stood for. Countless times in my own life time lost civilizations were dug up. People were even digging them up in ancient times. Even Scotland has their own versions of people and societies that were lost for thousands of years to be rediscovered when storms or floods unearth them. Lol, it is both funny and fascinating that all we know about the vast roman empire, one that is only a few thousand years old, in England; is through the work of modern man in just the last 100 to 200 years or so (1880). This flourishing hot spring (Bath) was a destination throughout the 17th century then one day the river was low and bam, a pristine remnant of perhaps the greatest empire man has known was setting below the modern city. I find that and countless other examples fascinating. The romans kept decent documentation but this and others went forgotton for almost a millenium.

I doubt that pre-history man made any sort of acheivment beyond simple tools, but I don't rule out the extreme possibility that someone may have discovered that lightning holds a power that can be harnessed. The problem is, if that was the case (and I only use that as a single example) the knowledge was destroyed and lost. A few generations worth of information passed on might add up to a single lifetime of information. At this point any reference to what pre-historic man knew is solely based on speculation, except for what is discovered in dating devices and settlements of the period.

//Edit Forgot to mention another example:

look at the epic poems of the anglo/scasons beowulf
From my recolection, Anglo Saxxon came to be after or during the fall of the roman empire! History places it to be around 400-500 A.D. I think. Christian scholars where the ones' who wrote the poems down. I think there are even Germanic and Roman elements in the Anglo Saxxon culture. Well within the 70 lifetime event. Egypt - a vast empire - is already forgotten and possibly buried.