>aboriginals have lived in Australia for 80,000 years
>literally accomplished nothing
>were using sticks to hunt when Europeans arrived
>they sleep on the road, don't understand or care that cars will kill them
>Australia had to invent a special gas mix that doesn't get you high, because as soon as one was exposed to normal gas the only thing they did was sniff it and sleep
They have IQs of 50-60, something we would consider "retarded". As a result they were unable to fathom anything beyond food/sleep/pleasure. No matter how much time passed, they would have never advanced beyond the stone age. They hit a plateau.
What if we are the same? To a superintellegent alien lifeform we might appear "retarded". Maybe, for example, the explanation for "dark matter" and the solution to FTL travel were almost immediately obvious to them, but we would never be able to fathom them no matter how long we worked on it for. Perhaps the aboriginals worked on creating more efficient weapons than sticks but simply couldn't fathom using materials other than wood.
A depressing possibility then is that a species' intelligence determines the hard ceiling of it's scientific and technological advancement, not just the speed of progress. And perhaps no sufficiently intelligent species can exist, explaining the Fermi paradox.