Twenty thousand years ago, the last Ice Age was at its frozen peak.
While some of our ancestors were making a living in what is now Europe, they were pressed between the permanent ice fields that covered all of Scandinavia and the mountains of the Pyrenees and Alps.
Much of our present-day oceans was locked up in vast ice sheets, lowering the sea level by as much as a hundred metres lower than it is today.
It was a time of scarcity and risk. Cave bears, Ursus spelaeus, at once a food source and skilled predator, enjoyed the same hunting grounds, similar prey and competed for many of the same shelters. Cave hyena, Crocuta spelaea, also looked to these shelters and while smaller, were encountered as packs.
Beyond days filled with an endless search for food, primarily through scavenging off the kills of hyena and others, there was also the no-small-feat of checking well-situated caves for other, rather scary, inhabitants.
Large prey could be taken down by an organized hunt. Wooly rhinoceros, Coelodonta antiquitatis, and majestic Irish Elk, Megaloceros giganteus, being two of the most prized.
For many, there was a regular cycle of gathering mollusks, seaweed, and birds eggs at the shoreline and picking the fungi and other small offerings from the woodland areas. Once an area had been harvested, the nomadic life continued, with groups moving from camp to camp and participating in organized annual hunts.
Nomadic groups gathered peacefully at places where large herds of bison, reindeer or other hard to hunt beasties were forced into a narrow channel to cross a mountain, river or stream. I'm impressed by this. Both at the organization of such large hunts and by the lack of evidence of warring between nomadic groups when scarcity was the norm.