Say, simultaneously across the world, everyone lost all their memories. Would the human race survive? We’d be thrown back to our primal state, with our minds a blank slate, and no knowledge or experiences to fall back on.
On the positive side, we’ve got: basic primal instincts, curiosity, the ability to learn and intelligence. We’ll also need a lot of luck.
To counter that, some of the difficulties we’ll face include:
Basic survival: satisfying hunger and thirst. Lack of water will kill us first. Do we know that liquid quenches thirst instinctively? If not, I’d say we’re stuffed. If so, how do we find water? We have no memories, so we’re dependent on what we can see or find. In most of the world, you’d have to go looking for a pond, lake or river. That’s one of the areas where luck would play an important part.
Finding food would be problematical. We’d have to learn what is edible, not poisonous and nutritious. Looking around at England in the winter, there’s very little to experiment with.
Communication would all but disappear. We wouldn’t have languages. If we are hurt, we could vocalize our feeling of pain, but would we be able to make more sophisticated sounds that would be understood, like, say, compassion? How long would it take to build up languages and learning to write and draw?
All existing relationships would vanish. We wouldn’t know who our partners, friends, children or parents were. An inate bond with the latter two might remain. Creating new partnerships and friendships would happen fairly quickly, but how long would it take to reorder society?
Everything we see would initially be a mystery to us. We’d learn quickly that houses provide shelter, but getting in to them at first would be puzzling. The function of doors and door handles would have to be learnt. I suspect we’d break through windows first, learning along the way that broken glass is dangerous and painful.
All the utilities would soon cease to function, even if we knew that turning a tap produces water. We’d defecate and urinate where we stood until we learnt that that spreads diseases. Medicine would have to be reinvented. We’d find books with pictures that we could learn from, but getting even close to the levels of civilisation that we would now consider to be basic would take a very long time. Not as long as it has taken us to get to where we are now, because homo sapiens is more developed than when we started out, but, it would be, I suspect, in the order of centuries.
Or am I being too pessimistic?